What cover is this?

[TubeTruck]

This is the flexplate cover that was on my TH350. I don't believe it's the right one because only 1 of the bolts was in, the upper opposite the starter. Seems someone drilled a hole in the bell housing for the middle bolt hole on the starter side and used a bolt and nut.

Any ideas?

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[Dutch Rutter]

In a clutch it could be made to work. The one on my 700r4 is like that cast piece you have. The one I used to have with my th400 was a stamped steel type and mounted the way your trans shows. I'm guessing (I've never had a th350) that you should have the stamped steel type.

Edit: kind of like this one https://www.speedwaymotors.com/GM-TH-350-TH-400-Flywheel-Flexplate-Dust-Cover-Black,231383.html

 

[TubeTruck]

That was my guess, that it came off a 700r4

 

[78C10BigTen]

This is the flexplate cover that was on my TH350. I don't believe it's the right one because only 1 of the bolts was in, the upper opposite the starter. Seems someone drilled a hole in the bell housing for the middle bolt hole on the starter side and used a bolt and nut.

Any ideas?

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If you need a th350 cover ive got one

 

[TubeTruck]

If you need a th350 cover ive got one

Thanks but I'm going to run it open for now. I don't wheel the truck and hopefully will be putting the 4L80e in by the end of summer.

 

[nvrenuf]

The transmission shown in the first pic is a regular case while the aluminum converter cover is for an "HD" case. The regular cases use a stamped steel / tin cover that's held on by small sheet metal screws. An "HD" case will have bosses cast in to the flange for 3/8" dia bolts that hold the thick converter cover on.

This is an HD case -

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[TubeTruck]

The transmission shown in the first pic is a regular case while the aluminum converter cover is for an "HD" case. The regular cases use a stamped steel / tin cover that's held on by small sheet metal screws. An "HD" case will have bosses cast in to the flange for 3/8" dia bolts that hold the thick converter cover on.

This is an HD case -

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TH350 though or 700r4?

 

[nvrenuf]

Same either way, including a 400.

As far as I know, the only difference in HD cases and covers is for the 4l80e.

 

[Craig 85]

The heavier cover was to attach the torque rods from the transmission cover to the bottom of the motor mounts. All 4x4 square body trucks with an auto trans had this.

 

[nvrenuf]

The heavier cover was to attach the torque rods from the transmission cover to the bottom of the motor mounts. All 4x4 square body trucks with an auto trans had this.

To add.... all after around '78 / '79, none before. 80's 2wd's could also have had undrilled HD cases with the thin stamped covers.

 

[QBuff02]

That's a heavy duty cast cover as you've read. I thought they were th400 specific until the overdrive trans came along, and see they work on them as well as a few other applications. In a perfect world they bolt to the bellhousing and there is a set of truss rods that go from the motor mounts (there's an extra set of brackets between the engine block and the motor mounts for this assembly to work) down to the cover that bolt into the bolt holes on the center of the cover, and then another rod that goes from the right side (3 o'clockish) bellhousing bolt back to the passenger side of the transfer case. It ties everything together and is important to keep from breaking bellhousings on transmissions in high torque/stress environments. Here's a pic of the driver side setup on mine for reference.

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[HOTFOOT]

same cover on my 80 k3500

 

[80BrownK10]

I have a thin stamped cover on my th350. It wasn't there when I got my truck. I got one from a junk yard. The guy said this is the light duty transmission that has been swapped in. I knew it was changed and just recently due to this forum found out I have a non lockup model where I should have a lockup as well. I had no idea the real differences in them though.

 

[TubeTruck]

That's a heavy duty cast cover as you've read. I thought they were th400 specific until the overdrive trans came along, and see they work on them as well as a few other applications. In a perfect world they bolt to the bellhousing and there is a set of truss rods that go from the motor mounts (there's an extra set of brackets between the engine block and the motor mounts for this assembly to work) down to the cover that bolt into the bolt holes on the center of the cover, and then another rod that goes from the right side (3 o'clockish) bellhousing bolt back to the passenger side of the transfer case. It ties everything together and is important to keep from breaking bellhousings on transmissions in high torque/stress environments. Here's a pic of the driver side setup on mine for reference.

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Yup, mine had the torque rods and plates sandwiched between the motor mounts and block. I'm guessing the transmission is not original since I had the plates, rods, trans cover, but the trans cover does not bolt to the transmission.