5 speed conversion with pics
 

Everyone,

I have started to convert my 1968 Chevy C10 shortbed from an automatic back to a stick. The transmission I decided to use was a NV3500 five speed from a 1994 Chevy C1500 pickup. I am going to document all the steps needed and the changes required to install this into my pickup. My truck was originally a 3 speed on the tree truck but had been converted to a TH350. The clutch pedal was hidden beneath the carpet (a nice surprise). When I started having transmission trouble I decided it would be more fun to go back to being a stick.

The first area I chose to change was the clutch linkage. The truck was originally made with mechanical linkage. The NV3500 uses hydraulic linkage. Mechanical cannot be retrofitted because the NV3500 has the clutch fork on the passenger side.

Re: 5 speed conversion with pics
 

I purchased a hydraulic clutch kit from LMC for a 1994 Chevy 1500 truck. It comes with a hydraulic master cylinder, the line, and a slave cylinder. The units are assembled, filled, and bled already so bolting it in is all that is required.

Re: 5 speed conversion with pics
 

The hydraulic master cylinder has to be level to work properly so the clutch rod could not be used in its present form. You may notice that the lever points down at about a 30 degree angle. This would have to change. Basically the "clock" of the lever had to change from 5 oclock to 3 oclock.

Re: 5 speed conversion with pics
 

Basically there are two different thoughts: make a bracket to change the angle or - (the way I am going) cut off the shaft, rotate it, and weld it back on. I wanted it this way so that I could make it look like that was the way it was supposed to be instead of something I cobbled together. Here are the pictures of the clutch pedal before and after welding. The first picture is of the pedal assembly in the truck. Notice the angle of the bracket. The second is of the pedal in my vice. Notice the sharpie mark on the shaft. This is the angle the assembly needs to be at to work with the new hydraulic master cylinder. The next one is the pedal after I cut off the shaft and tack welded it in the correct position. The last two are of the bracket after it was tack welded.

Re: 5 speed conversion with pics
 

Is the trans manual speedo with cable gear or elec pulsed? that was my problem with a 96' 5speed.

Re: 5 speed conversion with pics
 

It is electric pulse. My plan is to switch the gage cluster to the cyberdyne blue ice gages. The cool thing about the cyberdyne setup is that you turn it on with the parking lights on and it will enter set mode. Then you bring the truck up to 45 mph and hit the set button. Then the speedo is set. No other calibrations needed. I have one in my 1990 Nissan 240sx. I used a handheld GPS to set it. Since it is so easy to set it will work with any tire/gear combination easily.

Re: 5 speed conversion with pics
 

So far I have the clutch pedal finished and painted. I didnt think a picture of it would have been warranted. Hopefully my clock is correct. I am hoping that with the lever changed to straight up and down when I push in the clutch pedal it will have enough throw to completely engage the slave cylinder. Until the lever is installed I really won't know. I am waiting to continue the saga until the front end is pulled off of my truck. My engine is broken and I am pulling the entire front end off to make it easier to take the engine and transmission out and also give me room to work the clutch master cylinder. I also thought while it was off to weld off all the holes, paint the firewall, and put in new inner fenders. I figured while the whole front end is off the pictures will be much easier to work.

For the other questions, an NV3500 will NOT take huge amounts of torque. Maybe 350 lb/ft tops. No dropping the clutch or power shifting. For how I drive though it should be great. I am really stoked about putting it in so I can get overdrive.

Re: 5 speed conversion with pics
 

OK. I finally got the front end off and the engine and transmssion pulled. You do not have to go this far to do the swap. I just did it because my inner fenders were severely rusted along with the radiator core support. Plus having the front end off makes the engine pull soooo much easier.

Re: 5 speed conversion with pics
 

I installed the clutch pedal back into the truck with the updated clock. I found that I had to grind my weld a little better so it would fit. I also had to widen the bolt slot in the end so the clutch lever could fit flush against the shaft instead of 1/8th of an inch deeper. After I got the clutch lever installed I used the master cylinder rod and a level to figure out where to drill the hole. Once the hole was drilled I used the master cylinder to mark the holes for the mounting bracket. I will tell you this up front, I don't like the choice I made for my master cylinder. The bracket's clock is roughly 2 oclock which puts the top bolt into the bracket for the brakes. I would say if you want to move it over about an inch or two add a spacer to the clutch lever. I am also unsure whether this will interfere with a power brake booster since I have not done this conversion yet. I am pretty sure I will be OK. I welded studs to the firewall so I wouldn't have to mess with bolts and nuts later. Here are pictures of the clutch pedal slot, the clutch lever, the rod, and the master cylinder.

Re: 5 speed conversion with pics
 

I tested the clutch pedal - all works as intended so far. I will know more once the clutch is hooked up. I don't anticipate any problems since it looks pretty straightforward. Next I will be fitting the transmission and engine back into the truck to see where the crossmember and hole for the shifter need to be. I have gotten a little sidetracked though with the immense level of corrosion on my radiator core support. As you can see, the only thing holding the core support to the truck was the fenders! It is supposed to be the other way around! Luckily I have a TIG and plenty of will to rebuild it. I am cheap so I don't want to spend $300 to get one from LMC. If I fail in my repair (not likely) I will buy it. I also have some repairs to do on the cab that I wasn't expecting.

Re: 5 speed conversion with pics
 

Can someone go and measure from the firewall to the start of their power brake booster? I need to know if my new clutch master cylinder is going to be a problem. I am thinking now that it probably will be. The only way I can think of to get the master cylinder out of the way is to move it two inches or so to the left (on the firewall side). I can do this by making a spacer and welding it to the clutch lever. You can't just use a spacer between there because it will cause a bind in the linkage when you push the pedal. I am also thinking now that it was a mistake to weld in the bolts. If I am going to leave the master cylinder where it is I am going to drill the head off of the bolt that is in the brake bracket so it can be taken off to paint. Duh!!!!!!

Re: 5 speed conversion with pics
 

I think that you'll have a problem with the booster having the clutch there.

I would recommend, since you have the fab skills, to mount it on the other side of the master. I'm pretty sure you can get it over there above the junction block for the wiring, but you'd obviously have to "re-redo" the clutch linkage.

I'll take measurements & pictures of my master & booster when I get home tonight.

I love the project, & will be following closely as I want to put a NV4500 with hyd clutch in my blazer someday. Or maybe i'll just swap in the Duramax with it's 6-sp. Decisions, Decisions.....

Later,

Buddy

Re: 5 speed conversion with pics
 

I had a friend go and measure his power brake booster to see if I was going to have any issues. His measured 7 5/8 from the top bolt to the top bolt and 8 inches at the bottom bolt to bottom bolt. The clutch master cylinder is 7 inches long. I think I lucked out there. If it doesn't work well I can always move it over a little more. The reason I didn't want to put it on the right side of the brake master cylinder is I believe I would have a problem with getting enough push on the clutch master cylinder without the linkage binding. The clutch pedal itself is on a much bigger arc than the small clutch lever is. I was able to control the up/down movement easier on a smaller arm.

Re: 5 speed conversion with pics
 

mdlackey, i am also using a nv3500 and my original 6 cyl crossmember could not be used. I have an auto crossmember which attaches to the rear part of the tranny just like an automatic. The original 6 crossmember does not drop low enough in the middle to this tranny with the original crossmember.

Re: 5 speed conversion with pics
 

How much does the clutch linkage cost?What about an nv4500 would it be the same for the swap?
Shane

Re: 5 speed conversion with pics
 

when i look at my european cars hydraulic cluch i see 2 band steel straps inside the cab running from the bolts of the clutchcylinder to the dash itself to prevent it from moving about .
that should be a pretty eazy solution on youre truck making straps that bolt from the cylinder to the mounting of the steeringcolumb or sumtin simulair

Re: 5 speed conversion with pics
 

Chevybill, which auto x-member did you end up using? Do you have pics of the final install that you could share?

Jody, any new updates on your status?

Thanks,
Dave

Re: 5 speed conversion with pics
 

My crossmember came from www.performanceonline.com. I purchased tubular engine mounts and the crossmember at the same time.
I have no pics, truck is still in building stage and I am trying to figure out how I am going to make clutch linkage work.

Re: 5 speed conversion with pics
 

I would love to see pictures of everyone elses conversion so I can see some stuff I haven't done yet. Pictures of interest would be the in the cab shots with the hole for the shifter measurement from the center front of the hump. I also agree about the crossmember. I will be using an automatic crossmember since that is what I have. I didn't even think about the height so thank you for that! I will check the angle with my handy dandy angle finder when I put in the tranny. Hopefully it will be 0 degrees. I also don't know about the driveshaft yet. My NV3500 came with the yoke of the old driveshaft and a piece of the old driveshaft. I haven't checked to see if the TH350 yoke and the NV3500 yoke are the same one. I will be putting the transmission/engine in this week for a test fitting. Hopefully all will go well. I will post some pictures.

Re: 5 speed conversion with pics
 

Any of you, doing this NV3500 conversion, have plans for a speedo connection? Believe that the NV3500 has an electric speedo connection, while our original trannys had mechanical cable connection.

Would like to stay with a "mechanical" connection, since I have parts for a cruise setup, but may be easier to go to an electronic setup ...

Thoughts?

Dave

Re: 5 speed conversion with pics
 

The clutch linkage cost me if I remember about $200 from LMC. I bought the hydraulic master, slave, and tubing all as a kit for a 1994 GMC 1500.


As for the NV4500 asked earlier, they are generally the same price I paid for in the junkyard and are more plentiful. If you are looking for an NV4500 look for a 4WD S10 with a 4.3L Chevy. It is the exact one you will need. The NV3500 is for 2WD, NV4500 for 4WD.

Re: 5 speed conversion with pics
 

Where'd you get that information?

No S-10 ever came with the NV4500. The NV4500 is a HD (big) transmission for 3/4 & 1-ton applications. They are the transmissions that replaced the SM465 4-sp from the 3/4 & 1-ton trucks & added an OD gear. They were pu in behind the cummins diesel on dodge trucks & the big block & 6.5 TD in GM products. They can handle about 450 hp & 500 lb-ft in stock trim.

An NV3500 is a good candidate for this swap, but it's limit is about 250 hp/300 lb-ft. They did come in the S-10, but I'm not sure what years.

Also, the NV4500 has a separate bellhousing, whereas the NV3500 has an integral bellhousing.

HTH,

Buddy

Re: 5 speed conversion with pics
 

Hey guys ...

Guess I'm the "guinea pig" ...

I did mount the master cylinder in front of the clutch pedal, instead of where the clutch rod penetrated the firewall. I removed the clutch pedal return spring, and used another bolt/spacer/nut setup to get the geometry close. TONS of leg effort to get about 1.5"-2" of pedal travel and hitting the end of the clutch travel ... nowhere close to the floorboard. See pics to see how it mounted up ... guess it was too easy to be the final setup. Moving the master cylinder higher on the firewall to get it closer to the pedals pivot point .. hence greater leverage and less leg effort will put it too close to the steering shaft, IMHO. Thoughts?

Was there a "clutch return spring" in the '90's NV3500 that made sure it pulled the clutch arm and throwout bearing off of the pressure plate? Noticed that the output shaft on the tranny is turning while in neutral, and stops when I depress the clutch. Would've been in the bellhousing assembly, if it were anywhere.

Currently, I have a single piece of 1/8" wall 1.5" square tubing that is holding the tranny in place. Have it drilled for the transmission mounting bolt. Will probably have another length of it welded to it for additional strength ... don't know if it is REALLY needed ... but just being cautious ... and will have 1/8" right angles welded to each end, then drilled so it can be mounted to the frame rails.

Anybody else have any updates and pics on their conversions?

Looking forward to hearing from all of you ...

Dave

Re: 5 speed conversion with pics
 

mdlackey, That looks really good, I have a later transmission that does not have the separate slave cylinder down on the bellhousing. I have to come up with a bracket that holds the actuating cylinder in the same location that you mounted your clutch master cylinder.

Have you driven your truck yet with this clutch setup?

As far as speedometer, I am using an electronic autometer speedo that is supposed to work with this tranny. Autometer 1405 designer black series.

Re: 5 speed conversion with pics
 

Nope, haven't driven it, yet ... really concerned about what I'm going to have to do for the proper clutch articulation. Sounds great, thought, with just headers ... :metal:

Had driveshaft shortened, but it may not have been enough ... may need another 1/2" or so. Just too tight, when trying to mount back in to place. The "longer" one was the original, and it was shortened by about 6". The "shorter" one was from the '94 truck, and was TOO short. Plus, you'll see the difference in the end splines, where the intermediate shaft mates up with the rear driveshaft ... 10 spline versus ?? spline (27?) ...

Anybody figured out the "hump" over the tranny yet?

Dave

Re: 5 speed conversion with pics
 

Have you engaged your clutch yet and changed gears with the engine running? Do you have the clutch fully operational yet?

I was able to use my original driveshaft. Engine is in V-8 position, I was able to use my original yoke as well no cutting what so ever.

Re: 5 speed conversion with pics
 

you might want to try to find a smaller diameter clutchmaster from somewhere else so you need more travel to shift the same amount of hydraulic fluid , that should solve the exessive force needed to push the pedal down too

Re: 5 speed conversion with pics
 

Guys, sorry it took me so long to reply to some of these - I have been doing extensive rework on my radiator core support. Now that it is done I will be putting the engine and transmission into the truck for final measurements. So far I know the NV3500 is 7 inches longer than a TH350 from the mount so I am estimating that the crossmember will have to come back that far. Thanks for the info about the height using an automatic crossmember. I think I will make my own crossmember so I can set the output degrees to zero like it should be. I haven't even looked at the driveshaft yet so I don't know what kind of work I will have to do there.

As far as I was told, the NV3500 was in full size pickups and S10s with a 4.3L from 1992 to 1998. The NV4500 is a 4WD transmission. Here is a link if you want more info on it. http://www.nv4500.com/

Re: 5 speed conversion with pics
 

I'm having my own x-member fabricated, as well. If you guys know of a way to 0 the angle of the intermediate shaft to the carrier bearing, I'm all ears ... I'll take some pics, tomorrow, after I have my fab-ed one in place. Having to have my draveshaft cut another 1", as it sits way too far back in the carrier bearing mounting position. So roughly 7" would've been the total length removed from the original driveshaft.

For S&'G's, last week, I placed my stock original x-member in the framerails, just to see how the tranny would sit ... seemed way too low.
I'm really having to think about moving the master cylinder further up the firewall, so that more travel with greater leverege is seen.

On a side note, I cut my tranny "hump" to accomadate the new position of the shifter. Outside of the very top of the shifter housing ... the part I cut to clear ... there aren't any other "clearance" problems. Having a patch plate welded over the old hole, tomorrow.

New pics from anyone else?

Dave

Re: 5 speed conversion with pics
 

Well, I'm looking for feedback/direction ...

Below are pics of my drive angle ... YES, the intermediate shaft is too short by about 3/8" minimum ... the carrier bearing mount is at the very front of the mounting holes of the frame support. Also, you can see that the shaft is at an upward angle from that bearing mount. Looking at the angle of the front U-joint, right behind the tranny output shaft "mount", the wngle isn't too bad ... pretty straight .. might be able to drop it down a little more.

My question is ... would you rather have a front u-joint angle or one held by the rubber of the carrier bearing? Or is a redesign all together?

For those who were looking, you can see the tranny hump and shifter coming through it ...

Anyone thouhts, feedback, or updates on your own projects would be appreciated ... there are enough of us out here!!!

Dave

Re: 5 speed conversion with pics
 

... and the gear shifter pic ...

Did I mention before that my truck is kind of a "beater"? Working on the "mechanics" before the "asthetics" ... :)

Dave

Re: 5 speed conversion with pics
 

Well, I had to have a new length of "pipe" made for my prop shaft, since I mis-measured the 2nd cut. The initial cut of my original prop shaft (roughly 6") was about right ... should've been about 5 1/2" total.

HOWEVER, my NV3500/MG5 tranny came out of a '94 GMC 1500 ... the "front"/prop shaft u-joint, right behind the tranny needed to measure 3 5/8" x 3 5/8". My 68's u-joint was 3 5/8" x 3 3/4". Seemed to be a difference between the '94 Chevy and the '94 GMC, but could've been a mis-quote of part number and part ...

3 5/8" x 3 5/8" u-joint: PDQ part # 2-0053 (Pep Boys)
U-joint strap kit: NAPA part # 260-4178

Now, I have to try and get my drive angles within spec. Believe that I may have to use a spacer to raise the carrier bearing, rarther than lower the rear of the tranny ... starts to put a real angle on the prop shaft and believe that it will start to stress the engine mounts, too.

Anyone know if a return spring ... or anything for that matter ... was used on the VN3500/MG5 trannys to keep the throwout bearing off of the pressure plate spines?

Pics to follow ...

Thanks,
Dave

Re: 5 speed conversion with pics
 

Update ... Drilled and bolted the x-member into place and tigtened the u-joint straps on the prop shafts u-joints. Was able to drive the truck around the block today. Outside of the EXTREMELY short clutch throw that I mentioned in a posting earlier, it drove well.

Outstanding concerns ...

1. EXTREMELY short clutch throw
2. Drive line angles

Anyone have thoughts?

Dave

Re: 5 speed conversion with pics
 

The extremely short clutch throw is probabl due to the master cylinder rod pivot point being too far from the clutch pedal point.
I'm going to be converting to hydro clutch, (nv4500 soon), and the best way I've come up with to get the correct length for the pivot point is to measure the stock clutch pedal out of say, a 94 Chevy with a manual trans and hydro clutch.
I haven't gotten around to finding one to measure yet though.

The drive line angles...I didn't read all the posts, (yet), but I did see somebody mentioned 0 degrees. I don't think that would be correct.
The crankshaft centerline isn't "level" when an engine is installed. The carburetor pad should be level, or close to it.
The important thing on driveline angles is that the transmission output shaft angle matches the rearend pinion angle. Or as close as possible.

Re: 5 speed conversion with pics
 

454, yeah I figured that the further up the clutch pedal arm I go, the easier the throw will become. Just hope I don't run out of room, if I plan on installing a brake booster later. I may have to relocate back over to the passenger side of the brake master cylinder. Wanted to stay away from this since that would put the clutch master cylinder right over ... or close proximity to ... my number 7 cylinder's header tube.

Anyone know if the NV3500/4500's had a clutch return spring to keep the throwout bearing off of the pressure plate splines? Thinking I may have to mock one up.

Thanks,
Dave

Re: 5 speed conversion with pics
 

The NV 4500 I put in mine did not have a return spring. I am running the master on the driver side with a brake booster with know trouble. I did have the same problem of short throw and I moved the rod closer to thepivit. I then had to add a plate to my peddal are because the rod was to short on the master I used and I wanted my brake and clutch to be at the same height. I have been running this set upfor over a year and realy like it. My throw is a little less than a stock hydro system but not much, since I am lazy and dont like to have to pump my leg up and down every time I shift, I like it.

Re: 5 speed conversion with pics
 

I don't think hydro clutch's have a spring return. I think the throwout bearing rides on the pressure plate fingers all the time.
Not the best idea IMO , but I don't know any way around it yet.

Re: 5 speed conversion with pics
 

mdlackey, your transmission has a seperate bellhousing, correct?
The reason I ask is from what I can see in your pics you have a NV4500 trans.
I think we have 2 different kinds of transmission conversions going on in this thread.

jodydewey has a NV3500, (integral [spelling?] bellhousing)
mdlackey has a NV4500, (seperate bolt on bellhousing)

These are completely different transmissions so the crossmember and driveshaft specs will be different between the two, but the hydro clutch setups are almost identical.


NV4500; (notice the shift tower and crossmember mount) This is a 4x4 version but the only difference is the ouput shaft and output housing.
http://67-72chevytrucks.com/gallery/...93/NV45003.jpg

NV3500; (Had this one in my S-10, 4 sale for parts!LOL)
http://67-72chevytrucks.com/gallery/...093/5speed.jpg

Bolt on shifter towers for the NV3500 above;
http://67-72chevytrucks.com/gallery/...edshifters.jpg

Newer style NV3500; (This one belongs to a buddy of mine)
http://67-72chevytrucks.com/gallery/...93/nv35002.jpg

http://67-72chevytrucks.com/gallery/...93/nv35001.jpg



I've also got a few pics of different hydro clutch setups, (in 67-72 trucks), I'm working on uploading them so I can post 'em here.

Stay tuned!

Re: 5 speed conversion with pics
 

jodydewey, if you need a little extra room for your brake booster you could gain a little by setting your clutch master cylinder against the firewall. You'll have to enlarge the hole where the rod goes through.
Make it big enough the rear portion of the master cylinder will go through the firewall.
Gain you about 3/8 of an inch?

http://67-72chevytrucks.com/gallery/...Truck20031.jpg

Re: 5 speed conversion with pics
 

I just rememberd the return spring is built into the slave cylinder. when you buy then new they have a strap to hold them in the in position.