Oil pan bolt spacing measurements

[dbrannon79]

Hello all, Just a quick post hoping that someone out there might have an old 6.5 or 6.2 block sitting where they could measure the center to center measurements between bolt holes on the oil pan close to where the starter bracket area is. I’m working on a last stitch effort to make a bracket to help stabilize the starter from torquing movement when cranking that would essentially wedge a piece of steel between the block and the starter but would be held by two of the oil pan mountings bolts

to my explanation as to why. The other day I almost got stuck out of town when cranking my truck up. The rear bracket on the starter bent shearing off the stud on the starter for the bracket, and twisted the rear starter motor housing and bending the outer starter bolt to the point where the motor was resting against the block at the oil pan!! I’ve sense replaced the flex plate, repaired the starter and installed new bolts but in looking at the design of the bracket and the rear stud on the starter, their just too flimsy and can’t take that kind of torquing! Yes to my knowledge everything was tight before this happened but the outer ear for the starter mounting bolt has been broken out and re-welded in the past. This is just a last effort to make it last maybe another year before I have to replace the engine.

 

[Wreckinball67]

This is the best I could do. Same side as the starter but a little bit forward of it. The motor is sitting on a wooden crate that my new GEP came on so I couldn't get to the exact location of the starter. I imagine the spacing is uniform. If someone has a oil pan gasket that might be better.
Good luck

 

[dbrannon79]

This is the best I could do. Same side as the starter but a little bit forward of it. The motor is sitting on a wooden crate that my new GEP came on so I couldn't get to the exact location of the starter. I imagine the spacing is uniform. If someone has a oil pan gasket that might be better.
Good luck

I couldn't make out where the threadded bolt holes are in the pic, but I hadn't thought of using the pan gasket until you mentioned it. I may run down to the local auto parts house and see if they have a gasket in stock. I can possibly take a pencil tracing between two holes and use as a template pattern. I'm just hoping that this idea of a support brace will help things. as the moment, with the new flywheel installed it cranks and starts perfectly but then again it worked flawlessly before for about a month until things started moving! I've gone through two bent rear brackets and two sets of starter bolts in the past 5 months. Only this time it was more severe. Thank the man above that the block repair didn't break!

 

[Will L.]

If you need more pics, i have one on an engine stand.

 

[dbrannon79]

If you need more pics, i have one on an engine stand.

if you have one, all I'm needing is the bolt spacing.

 

[Will L.]

3.350” Hard to show center to center so I show edge to edge which is the same.

 

[Will L.]

Kinda crazy to destroy the bracket. Never seen that unless the bolt came loose and it bent.

 

[dbrannon79]

Kinda crazy to destroy the bracket. Never seen that unless the bolt came loose and it bent.

I'm a aw myself, but the bracket did come loose from the stud on the starter on the first bracket. after I replaced the bracket I double nutted the stud and later it sheared off the stud. that must have been me over-tightening on the 1/4" stud! both times the brackets ended up with a slight bend toward the block and forcing the rear starter housing to slightly turn. On the pic you posted, the mounting point I'm looking at using are where the 8mm bolts are on the oil pan just behind the starter nose cone, about three or 4 bolt holes up from the rear of the block. to describe the idea better, it's taking a small piece of 1" x 1-1/2" angle iron long enough to use two of the oil pan bolts to hold in place. facing the angle upward where the 1-1/2" side would wedge it's self between the block and the starter motor giving the back side of the starter motor no room to push toward the block. what's been happening is the flex and bending of the bracket when cranking, the starter gear tries to push away from the ring gear pushing the rear of the starter closer to the block using the inner starter bolt as a pivot point. given the outer bolt and the broken and weld repaired ear on the block is now a weak point. I know this isn't the greatest idea but it's the only thing I've been able to come up with to try and keep this truck going for a little longer while saving some green paper to replace the motor!

 

[dbrannon79]

Here's a photo of the starter mounted after I got the flywheel replaced. I'm wanting to use the two bolts on the oil pan where the silver bolt is on the pan and the next one between the pan and the starter to mount. there is maybe an 1/8" to 3/16" or so clearance between the side of the starter motor and the block (pan mounting surface) where I would wedge the angle to keep this from happening if that makes better sense.

 

[EWC]

Are you able to fabricate ? Could you make a bracket that mounts onto the starter , where the bolts go into the starter , and wraps around to one of the trans bolts ?

 

[Will L.]

I really would want to look into everything closer. problem I see is that you have to have something wrong, like starter is made wrong or bushings worn bad, maybe something wrong with it's gear of the flywheel teeth aren't right.

Are those GM starter bolts? Ive seen issues with aftermarket ones.

It could be you over tightened and broke the bracket fastner- over tighteneing is the #1 most common error of mechanics, both pro and diy. The double nut one shearing off the stud could be same thing maybe?

If not- then there is far to much force from something wrong, and my concearn is you will just shear the tiny oil pan bolts or stud which ever you go with.

on Hummers/ hmmwv they use the p.o.s. direct drive starters and have a huge mount that goes to the motor mount. I would suggest something more like that. But seriously look into starter, flywheel, bolts, etc. because there is no reason you should have to go through the extra bracket.

The engine is starting, and not locked up, right?

 

[dbrannon79]

I really would want to look into everything closer. problem I see is that you have to have something wrong, like starter is made wrong or bushings worn bad, maybe something wrong with it's gear of the flywheel teeth aren't right.

Are those GM starter bolts? Ive seen issues with aftermarket ones.

It could be you over tightened and broke the bracket fastner- over tighteneing is the #1 most common error of mechanics, both pro and diy. The double nut one shearing off the stud could be same thing maybe?

If not- then there is far to much force from something wrong, and my concearn is you will just shear the tiny oil pan bolts or stud which ever you go with.

on Hummers/ hmmwv they use the p.o.s. direct drive starters and have a huge mount that goes to the motor mount. I would suggest something more like that. But seriously look into starter, flywheel, bolts, etc. because there is no reason you should have to go through the extra bracket.

The engine is starting, and not locked up, right?

right now since I have a new flywheel installed it cranks and starts just fine. And your right about breaking off the oil pan bolts, those small bolts wouldn't be able to take much stress. Going that route with a homemade bracket would have to be designed in a way not to allow those bolts to take to brute force!

I did use Dorman brand starter bolts from O'reillys both times. I'm just afraid this will happen again thinking "third time is a charm" (sarcastically speaking).

Both times this has happened, the bracket had ether came loose from the starter or like the second time where it sheared the stud has led me to believe the bracket and it's mounting was the cause. that and the fact that the outer starter bolt thread has been heli-coils that very well could have loosened the bolt enough to allow for movement. I'm cringing at the thought of using lock-tite on the starter bolts making it a problem if I have to replace the starter down the road with it being heli-coiled!

The bracket for the Hummers might be a better option instead of the flimsy one GM had. it just doesn't look like it's well designed to take much force. you wouldn't happen to have a pic of one or a part number would you? even one of those baby high torque starters might be an option too.

 

[dbrannon79]

Just googling online I found this photo. Would this be the starter bracket for the Hummers? this one looks as if it mounts to the block. Looks like a much stronger design compared to the GM bracket. maybe I could engineer this to work better vs my crazy idea I came up with!

 

[Will L.]

GET RID OF THE DOORMAN STARTER BOLTS!!! I had nothing but problems with those over the years. Had a guy bring over GM bolts and calipers to show me the hat my problem was- I would be willing to bet that is your issue.

You wont be able to use the hummer one. The starter is like 4” longer. Also incase anyone tries- the hmmwv/hummer starter bolts are different also, like 1/4” longer for shimming. NEVER reuse shim-able starter bolts (even old 6.2) with the new high torque starters. It is a pile of hurt coming over a $10 cost.

 

[dbrannon79]

looked up the GM # 15544950 and placed an order.

 

[dbrannon79]

Just to verify, on torque specs for the starter bolts. did I read correctly from another thread that the starter bolts should be 40ft/lbs and the bracket should be 30ft/lbs? I think I'm going to verify the torque on each bolt / nut and then check them once a week for a while and see if I can tell if something is loosening up after I get the GM starter bolts and toss the Doorman bolts!

 

[ak diesel driver]

The 30 seems high for a 1/4" bolt

 

[ak diesel driver]

Specs I just looked up showed 9 for a grade 8

 

[dbrannon79]

Specs I just looked up showed 9 for a grade 8

I was thinking the same thing. looked as a site that gave the specs per bolt size and it showed 33ft'lb for a 10mm grade 8.8 which is the grade stamped on the starter bolts. is there a torque spec for the starter bolts in the book? I wish I had access to one!

 

[Wreckinball67]

Since we're on the subject of starters; what are your opinions on starter upgrades say from Powermaster? I still have my original starter and I'm considering an upgrade to go with my new GEP motor.