very frustrated

[halfadeuce]

Hello everyone, I've been issues with my 71 suburban. I know its a combination of a lot of little things but I need some advice. Can bad timing- Carb tuning cause the engine to kick back when I go to start it? I have a problem with the starter engaging the flexplate I've tried 3 different ones and they seem to work for a couple of days then they either grind or stick to the flexplate. It happens more when the truck doesn't fire up right away. The more I crank it the more likely the starter will grind. This morning it was really cold and the truck started then died. I was giving plenty of gas but it still died and I couldn't get it to fire up again. I know the Carb needs to be rebuilt because it leaks from a few spots but where would the best place to start be. This is my family car and right now its not very reliable. Any advice would be appreciated. I checked the block and it appears to be a 77-79 350. Thanks
Posted via Mobile Device

[vectorit]

I would verify that the engine timing is correct.

Is the engine fairly new/rebuilt? I ask because if it has a lot of mileage, the timing chain could be sloppy causing the timing to fluctuate.

What kind of ignition? Points, GM HEI, or after market brand like Mallory or MSD?

Automatic or manual transmission? This is so we can understand the type of starter mounting.

[halfadeuce]

To be honest I don't know if the engine has been rebuilt recently. I bought the truck about 8 months ago off of Craigslist from a guy in AZ. It is an automatic with a 350 tranny, the hei ignition appears to be stock. I had to pull out and reinstall it because it was turned way clockwise just to run decent when I got it. It smokes a little while idling from the drivers side pipe. The timing is at 12-14 degrees. Any lower and it idles like crap and is non responsive. When I set the timing I disconnected the hose from the distributor and capped it but the timing stayed where it was at, so I set it where it idled ok. The truck looks like it sat for a while and the guy cleaned up what he could to sell it.
Posted via Mobile Device

[klmore]

I think Vectorit may be correct. It sounds like a higher mileage motor that could be having some problems. I would do a compression check then check the timing chain for slop. Once you know what you are working with you can start moving on to other possibilities.

[halfadeuce]

UPDATE.. I had a mechanic take a look at my truck and confirm what I suspected. The flexplate is shot, the carb needs to be rebuilt or replaced, the timing is off and the vacuum advance isn't working, plus my oil pan is leaking and when I do get the truck started it smokes out of the drivers side pipe. He said the carb may be causing the smoke but id have to get a good carb on it to confirm. I still haven't run a compression test but I hope to do so this weekend. I have the oppurtunity to purchase an engine with a new edelbrock carb, new flexplate, new oil pan and some extra parts for a very good price. It would solve 3 of those issues right away but I'm not sure how to tell if that engine is a freshly rebuilt or low mile engine, or if someone just cleaned it up to sell. I know just on the new parts it comes with its still a good deal. Any advice will be appreciated. Thanks.
Posted via Mobile Device

[BB72CHEVKT]

You might want to make sure the blocked isn't cracked down by the starter and causing the problem.

[halfadeuce]

Do you mean unbolt the starter and check where it mounts for cracks? I have removed that starter a lot and never noticed anything but then again I never thought that may be the cause. Thanks ill check it out.
Posted via Mobile Device
Posted via Mobile Device

[BB72CHEVKT]

After some research it looks like you need to check for cracking around the bolt holes for the starter. There originally was a brace coming off the motor that attached to the starter to prevent this from happening but most brackets have been removed over time. Someone correct me if I am wrong.

[gearboxx70]

You are very correct on the cracked starter mounts. I've seen a couple of these, and seen some of the damage it can do to flywheels/flexplates. LMC Truck sells the starter to motor braces, but they don't look like the factory braces I've seen in the past. I guess look don't matter as much as long as they serve their purpose.

[halfadeuce]

Update. The deal with the engine fell through. So it looks like I'm gonna have to do what I can with my engine. Is there any way to get to the flexplate without completely removing the transmission? If not do I have to remove both drive shafts or can I unbolt from the rear end and slide it back?
Posted via Mobile Device

[Racer2172]

On the two piece drive shaft it most likely has a carrier bearing so if you unbolt that and from the rear end you could slide the whole driveshaft back. Or just remove the front portion of the drive shaft though it can be stubborn when dealing with the carrier bearing, its a good time while you have it apart to check it and all your u joints. Removing the flexplate will be easiest if you drop the transmisson. you might be able to unbolt it and slide it back but if it was me i would drop it and make use of the extra space to get the bolts out that hold the flexplate to the crank. Or you could just pull the motor and leave the transmission which would allow you to check the timing chain and other issues while your at it. Hope this helps. Welcome to the board.

[gearboxx70]

When I had my trans out for a rebuild and new clutch, I had to pull the 2 bolts that hold the carrier bearing to get enough clearance to get the driveline out. That may be different than yours since these trucks came with a few different carrier bearing designs. It was no big deal for me since I also replaced the carrier while I was under the truck.
Racer2172 is correct though... You either drop the tranny, or pull the motor. Besides checking out your timing chain and such, pulling your motor will allow better access to the starter mounting holes should you need it. And if you have a leaky pan gasket, this would also be the time to change out that (and take a rare peek into your bottom end to check out the health of that).
But then there's something to be said for dropping your tranny too. Most shops will do a re-seal for less than $200.

Options....

[halfadeuce]

I went home for lunch and was able to unbolt the carrier bearing and got the driveshaft out. I put a baggie on the rear of the tranny to contain some of the fluid. I don't have a hoist to pull the engine so I have to do what I can from below. I loosened the hoses to the tranny cooler and left back to work. Tonight I'm hoping to unbolt the tranny from the engine and possibly get it on the ground. Is there anything I should be aware of? This is the first time I do any of this. Thanks for your help.
Posted via Mobile Device

[gearboxx70]

Make sure your tranny dipstick doesn't have a tab bolted to the back of the head like some do. Also look for the vacuum line on the passenger side that goes from the carb or manifold to the vacuum actuator on the tranny near the tail shaft.
Make sure you slide the tranny STRAIGHT back until the input shaft (the shaft that sticks out of the front of the tranny into the torque converter) is free of the torque converter.
Oh, almost forgot, put a jackstand or blocks under the back of the oil pan so the engine doesn't rock back and break your dist. cap against the firewall. There's not alot of space there with the HEI style cap.
I'm just hangin' around the house tonight, and I've been where you are. If you need someone to talk you through something real quick, call me... 530-305-8506. I hit the sack around 9 to get up early for work, but I'll be availible til then.

[vectorit]

I've never had to do what you are about to attempt.

But here are my .02

I would un bolt the torque converter, then take some wire and try to secure it snugly against the transmission. You don't want it to disengage from the pump housing inside the transmission while you are wrangling the transmission around, then causing more headaches when you go to re assemble every thing (meaning that the TC becoming disengaged from the pump, and not letting you put everything back together easily).

I may be over thinking that, so someone else may chime in with clearer more experienced thoughts.

pull all the spark plugs out, so that you can turn the crank easier.

make sure to disconnect the reverse light wire, trans linkage, and vacuum line.

You may want to get a jack with a piece of wood to support the engine, put a tiny bit of upward pressure on the engine before you try to move the trans backwards. This should keep the engine from tilting back enough to cause you trouble.

[gearboxx70]

Thank you vectorit. Yes wiring the TC to the tranny would probably be easier. Takes some thin wrenches to get into the TC bolts though.

[Racer2172]

A lot of rental equipment places, rent engine hoists and transmission jacks.
Posted via Mobile Device

[halfadeuce]

You guys are awesome. So far I've pulled the distributor. I will pull the plugs linkage and start on the torque converter. Thanks guys ill keep you posted.
Posted via Mobile Device

[unclesalty]

something I came across on the internet (so it must be true) sbc had metric starter bolts on the later blocks (gen IIs?) they were slightly different diameter wise, if you mixed them up, the extra side play from the smaller diameter bolts will allow the starter motor to cock. I guess there are adaptor sleeves you can use to correct this.
(The starter bolt shoulders are knurled so they fit the bolt holes snug)-just something else to check, wont cost you anything- you may have gotten an oddball part (re-man) somewhere, it happens. Good luck. Usually a kickback= too much timing, too far advanced.Check you plug wires unless she runs real smooth-

[halfadeuce]

Hey everyone, so here's an update. I ended up pulling the engine and tranny out to replace the oil pan gasket and flexplate. Once it was out we saw the heads needed a valve job and the bearings were pretty scuffed. So off to be rebuilt she went. Money's been tight so I spent what I can cleaning up the engine bay and cleaning all the accessories because I can't just go buy everything new. Long story short, engine is in looks good and I just have a few loose ends, mainly a freakin starter that refuses to mesh with a flexplate. That was the original problem. I purchased a starter bracket from the oc truck shop and the holes don't line up. I'm drilling a hole into that bracket to see if I can make it work. I've been working on getting it drivable for the past week straight after work. Any advice will be appreciated.
Posted via Mobile Device
Posted via Mobile Device

[gearboxx70]

There are two flexplates that typically bolt up to SBC. There's not a huge amount of difference between them size-wise, so you may have the larger one and a starter designed for the smaller one. Or the bracket is designed for the smaller one. Either way, the problem is the same. I'm pretty sure the starter would use a slightly smaller gear to engage the larger flexplate. If you still have the packaging for the flexplate (assuming you bought a new one), check to see how many teeth it has (153 or 168). Then make sure you have the right starter for for that flexplate.

[halfadeuce]

Last night I took the passenger side header off to get the bracket on. I got it bolted up and tested the starter. It sounded ok. It wasnt grinding but I did notice that the bendix gear was not retracting all the way after cranking. It would sometimes but other times id have to push it back with a screwdriver. I am trying to get the shimming correct but I'm not sure how to only shim the outside bolt. Would you cut the shim and place it on the bolt kind of like a washer? Is the bendix going bad after all the test starting?
Posted via Mobile Device

[gearboxx70]

If you bought a rebuilt starter, the bendix or solenoid could be bad or marginal from the beginning. Typically, rebuilders test everything before, during and after assembly. But bad parts do get by the tests, especially if the rebuilder doesn't have quality in mind.
A weak bendix spring or solenoid could cause the problems you have. Also check the voltage going to the solenoid from the ignition switch. A voltage drop could cause issues that would look like a bad part.
As for shimming... Yes, you could cut up the shim. Or you could just find a washer the right thickness. But if you just have to shim one bolt, I'd be looking at why that is. Chevy starters shouldn't have to be shimmed at all. That's just how they were all designed. If you were working on a Ford, That would be another story! (Many Ford starters come with shim kits in the box. Hmmmm..... Just another reason to own Chevys?) Can you get any clear pics of the starter bolts and where/why you have to shim? If we could all see what's going on, it might be easier to diagnose the problem and get your Burb back where it belongs...On the road.

[halfadeuce]

I wish I knew how to put up pictures from my phone on here I can show you what I'm dealing with, the reason for the shims is that I'm going off the little 1/8 inch rod that came with the starter. I believe it goes between the bendix shaft and flexplate teeth to check clearance. With no shims there was a big gap between the shaft and teeth, I put a couple of washers on the outside bolt and it got closer. But its still not close enough and it binds. I've been reading that orileys starters fit pretty good. Should I "START" off fresh with another starter?
Posted via Mobile Device

[gearboxx70]

Let's go back to the engine and flexplate for a sec... What size engine? As I said before, there are 2 different size flexplates for Chevy engines, the 168 tooth being waaayyy more common. Also, some are drilled out with 2 bolt patterns to fit multiple applications. And there plates for internal balancing and external balancing (SBC=internal, BBC= external, EXCEPT small block 400 which is external!)
This may, or may not, be a dumb question (Like "is your computer plugged into a wall outlet and actually turned on?")... Is your flexplate installed correctly (i.e., the proper side of the flexplate facing the engine)?
Go back to the compatibility issue (Its free!)... Are the starter and flexplate compatible? If so, then look at the voltage going to the starter (Also free!).
If all else fails, look into a different starter.
By the way, posting photos is done with a photo hosting site such as photobucket, flickr, etc. I have a free photobucket acct. with a mobile ap. (Once again, free! Can you tell I dig free stuff?)