[79 Phoenix]

The 76 400 engine I'm putting in my GT-37 came out of a car with a TH400. Mine has the HD Muncie 3 speed manual and I'm using the original flywheel that came on the back of the original 350.

My service manual says to be sure to install the shims if the car has an automatic transmission. Does that mean to leave them out of it's a manual?

SEE PICTURE re: the shims I'm talking about.

[johnta1]

It would need the shims if it is not correct. Not sure why the manual said that. It would need to be checked to see if it does need shims.

[4zpeed]

In my experience standard transmission cars do not require shims, automatic transmission cars do and the number of shims does vary.


Frank

[steve25]

The test / check that I have used is to get one of those really big metal paper clips and bend it outwards so it has some straight length to .
This wire diameter is then used to check the clearance between the flywheel gear and the drive gear on the kicked out starter drive.

If the clip can’t feed in then you need however many shims it takes to get that clearance.

[mgarblik]

Yes, Pontiac says no shims required on manual trans cars. but that was 60 years ago. So many lousy rebuilt starters, engines rebuilt multiple times, sometimes some are needed. The best way to check is put starter on without solenoid. With your hand push solenoid plunger forward to engage flywheel fully. You should be able to insert an unfolded paper clip between the root of the flywheel teeth and the starter drive tooth. If too tight to pass through, add a shim. Or just put it together without any shims and see how it sounds. The starter will tell you if it needs a shim or two by how it sounds. Pretty simple process. Good luck.

[Dragncar]

I have never had any luck with OEM style shims.
When I bought my first Summit mini starter in the instructionsthey said to use a 1/8" drill bit in the root. I used a welding rod.
I needed to get closer and the instructions said to "tilt" the starter in with a washer under the outside bolt. A 1/2" flat washer did the trick.
Its been perfect on the 455 and perfect on the 461.
No issues, no grinding, no noise and never have had to replace a starter drive or a flex plate.

[4zpeed]

Of all the Pontiac's owned or worked on I've never used shims on a standard but automatics always required them. I would assume no difference in the block or starter so it has to be the size in flywheel vs flexplate. Not sure why that would be the case as far as regular production, seems to me one should be no different than the other. As mentioned though if there are changes made in parts it would make a difference. Beyond me why they would design a size difference but obviously they did.


Frank

[Aaron65]

I paint a few teeth on the flexplate with some art paint mixed with a drop of gear oil and spin the starter a few times to get a pattern; then I add or subtract shims if necessary. It only takes a minute or two.

[79 Phoenix]

Okay, thanks everybody for the help with this...just what I needed to know!

[Kenth]

f you put a 1/8" Allen key between the starter gear shaft and flexplate/flywheel teeth but not be able to twist the key you´re good.

I´ve been using the paper clip in the past with mixed success, the Allen key works every time.

[Schurkey]

Theoretically, you don't need to leave the solenoid off to pull the drive into engagement with the ring gear. The starter housing has a slot on the underside that you cram a pick or thin screwdriver into, which allows you to pry the starter drive rearward until it engages the ring gear.

Having said that, I've never done it that way (although I probably should start.) I just listen to the starter and deal with whatever shims are needed--thin or thick, multiple shims, half-a-shim under the inner, or the outer bolt. It is--sometimes--greatly frustrating.

[mgarblik]

Post #10 and 11 are great. I like the hex key idea for clearance and I did not know about the access slot to engage the starter drive. I learned 2 new things today and it's only 9:00 AM!

[burd]

It shows how to shim in the GM manuals too
I never had to shim A starter yet, but got this baggie of them in a tub of parts I bought off a guy.

[79 Phoenix]

Thanks Guys--All this will make more sense to me in a couple days after I get the engine off the stand, bolt on the flywheel and check the runout on the bell housing hole... Once that's right, then I will work with the starter and see where that's at... Hopefully all will look good without shims. The starter on the original engine had no shims but this is a different starter on a different engine.

[geeteeohguy]

Originally Posted by 4zpeed

Of all the Pontiac's owned or worked on I've never used shims on a standard but automatics always required them. I would assume no difference in the block or starter so it has to be the size in flywheel vs flexplate. Not sure why that would be the case as far as regular production, seems to me one should be no different than the other. As mentioned though if there are changes made in parts it would make a difference. Beyond me why they would design a size difference but obviously they did.


Frank

45+ years working on cars and Pontiacs, same here. Standard trans cars never need them and auto cars always do.

[tjs72lemans]

My 400 I rebuilt a few years ago with a 400 auto needed no shims. I used the paperclip method prying the starter gear into the flex plate. Starts quiet without issue.