Re: 89 GMC Cummins conversion
 

Sorry for not updating this thread but I sometimes procrastinate and other things have seemed to taken a priority over working on the truck. I am hoping to have the garage cleaned up in the next few days in order to pull it into the garage and get started again.

We are over halfway through basketball season and the boys are still undefeated. We are hoping they will make it to state this year. Here is a pic of one of the projects that I have been wanting to do for the last year and finally got around to doing for the school.

Thanks again for those of you following along.

Re: 89 GMC Cummins conversion
 

That's a very cool pair of ball racks! Good luck to your son's team too!

Re: 89 GMC Cummins conversion
 

Thanks Ryan. Well, Basketball is over and we ended up first in District and third in Division. Our record was 24 wins and one loss IIRC. The one loss kept us from moving on to State from Division. Vehicle will be in the garage by this weekend and I also moved my new storage building where I wanted it and now have a designated wood shop to boot.

Re: 89 GMC Cummins conversion
 

Dang that's some serious competition! Bring on the truck updates.

Re: 89 GMC Cummins conversion
 

COS, just read the whole thread. Great truck. Cool to see that family is a big priority for you. That new Int'l is killer. Could see just massaging that thing back to life from the wheels on up. Keeping patina but getting mechanicals, wiring, etc. in order. Very cool.

Re: 89 GMC Cummins conversion
 

LT7A, thanks for following along and your positive feedback. Yes, I have to admit that life revolves around my kid and my projects get pushed back.

The Int'l is just collecting rust for now. I am trying to get a title for it before I touch it. The license plate on it shows 1946 as the last year that it was registered. :lol:

I wired in the OBDII plug and mounted it just above the gas pedal underneath the dash. Locating it there kept me from having to extend any of the wires. I am reconsidering dropping the TC and resealing it for now because it seems that my low ATF levels are possibly a result of still trying to fill all the lines and such. As I previously mentioned, these Lokar dipsticks don't extend very far into the pan and therefore it is hard to sneak up on the correct level.

While greasing all the zerk fittings I found that one of my battery ground cables was no longer connected and that would explain why I needed to periodically charge the batteries. :lol: Lastly, I connected the Crank Position Sensor to the transmission controller and I will see if that changes anything.

While it is in the garage I will either make some nerf bars or pull the ones off my PSD and mount them on the GMC. I know my kid wants the ones of the PSD because they say "Smittybilt"on them and Smitty is his nickname. :lol:

Re: 89 GMC Cummins conversion
 

It sounds like you're making some head way. Every little bit helps. So I've heard. Haha :lol:

Re: 89 GMC Cummins conversion
 

Here are some updates for those of you still following along. Not sure if the OBD2 plug is wired correctly. When I connect my cheap code reader it shows "No Link." I have tried a few different configurations with no luck. Dawna, at Autoworld, is trying to help me out on this issue.

After crawling underneath the truck I noticed a few of the transmission oil pan bolts were wet. I had to remove the cross member to tighten up the rear pan bolts and noticed that the transmission mount was rubbing up against the pan. A little massaging with a BFH gave me the clearance needed to correct the problem. This probably wouldn't have been an issue with the factory pan.

I repaired the broken transfer case vent, extended the rear axle vent, and in the process of learning more on how to tune the PCS transmission controller. Anyone with a PCS controller on a 4L80E please chime in. Thanks for following.

Re: 89 GMC Cummins conversion
 

Looks good. That is a big ass pan.

Re: 89 GMC Cummins conversion
 

Chiming in, have one in my vette. I also have a tune that a guy sent me for a 4L80E behind a cummins, ended up going with the allison but I saved the tune jic. I can email that to you if you like.

Re: 89 GMC Cummins conversion
 

Awesome job with the swap everything looks nice and clean, I read through you build. The chrome wheels give it a nice look and I like what you did with the caps. I have a set of h2's that will be going on the K10 at some point and I might steal your idea with the caps.

Re: 89 GMC Cummins conversion
 

Thanks. I sure wish I could edit videos like you do.

Re: 89 GMC Cummins conversion
 

Mike, Thanks for sending me that tune for my transmission. I ended up using one that Dawna sent me that had been tweaked. It still needs some fine tuning due to the differences in vehicles such as: HP, Torque, gear ratios, tire size, etc....

It now goes into 4th and locks up the torque converter but it takes a looooooooooooooooooooooooooooooooong time to shift from 3rd to 4th. Once it hits 4th, it immediately locks up the TQ. The shift from 1st to 2nd is quite the opposite, it isn't in 1st for more than a few feet before upshifting. :uhmk:

Tje good news is that my boy got his license today. The bad news is that I have decided to make him buy his first vehicle. Of course we will match his contribution to the purchase, but I feel that this will help him in the long run. I'm sure some of you will agree with my decision and some of you won't. Of course if he wanted to fix up the International we could do that as well.

Re: 89 GMC Cummins conversion
 

So today I took the red truck for a little drive and put about 140 miles on her. I checked the mileage and it was 12.5 mpg, but that includes a lot of idling and short trips while tweaking the transmission tune. On my trip today most of the driving was at 75-80 mph. I'm sure the mileage will go up some after I fix the problem with the 3rd to 4th gear shift. I have to say that I got a lot of thumbs up from drivers in the two little towns that I went through. :metal:

Re: 89 GMC Cummins conversion
 

That's great to hear you're out there driving it again! I don't blame you one bit for making him but his ride. Or at least work for it. One of my brothers just used family vehicles and it took him a long time to appreciate having his own. I'm hoping to build my kids their first vehicles but that's just because I don't think it will be a good deal to have to buy them. We'll have to see when that time gets here. I've got a little time. Haha

Re: 89 GMC Cummins conversion
 

Wow! Just got off the phone with my insurance company and it turns out that adding my kid to the policy added $985.80 per year. :waah: Everyone said it would double and I'm glad it didn't but it did increase by 50%. All my vehicles are now for sale and I will be in the market for a horse and buggy. :lol: :lol:

Re: 89 GMC Cummins conversion
 

Will feed and hay be cheaper than a 50% increase of insurance? :lol:

Re: 89 GMC Cummins conversion
 

Probably will be cheaper right now as the price of hay sucks! LOL. So what was that tune like I sent ya? When did the converter lock up with it? On the vette I liked it to happen just after second gear. I never have been able to get a good solid 2-3 shift on the vette, just mushes into third. Never dared trying a 3-4 shift under full power as thats just too fast give the current condition of the car (old, stock drivelines, ect). Had one of my sons with me the last time I had it on the road, we were racing around with one of my buddies on his 1000 kawasaki and according to him we were a touch over 140 by his bike and the passenger T top just blew off! Talk about scare the s&*t out of us. I expected it to be splattered all over the road but it just got scraped up some. My kid and I looked at each other and said, well I think its time to head home!
Glad to hear its on the road! You bringing it to the dunes this summer?

Re: 89 GMC Cummins conversion
 

I haven't even tried the tune you sent me, I may try it on my next set of days off. Glad to hear that your out having some fun with the Vette. Maybe I should get my kid to buy a diesel Che-Vette. :lol: Do you remember the Chevette?

As for taking it to dunes, well let's just say it may have a new home in Texas before I make it down there.

Re: 89 GMC Cummins conversion
 

Mike- I tried you tune and it shifted into 4th sooner but would not unlock the converter for a longer time frame than it should. I was able to tweak Dawna's tune to where it shifts like it should now. It could use a little more fine tuning but it will have to wait for now. We got a couple of inches of moisture last week so everything is in full bloom so I have some yard work to do and a few other projects that need my attention.

Re: 89 GMC Cummins conversion
 

Glad you're getting it dialed in. I never really thought about it but these transmissions never came behind something even remotely similar to your motor.

Re: 89 GMC Cummins conversion
 

Thanks Marcus. It's nice to be able to adjust everything it does, but it can also be a little overwhelming for a novice. :lol: I really like your project and all the attention to detail you did to make it look like it came from the factory with that engine. I may try a 8.1 L swap one day and may have a few questions for you. :lol:

Re: 89 GMC Cummins conversion
 

Looks badass. Where did you get it?:metal:

Re: 89 GMC Cummins conversion
 

What alternator are you using?

Re: 89 GMC Cummins conversion
 

Thanks. The valve cover came from Jegs $194.00

I am running a first gen with an internal regulator. I have been running the same set up in my 88 for the last 10+years with no problems.