Tranny mount

[Linda]

Hi, I have a 51 cj3a and as I was getting ready to clean and paint the frame I noticed were the tranny cross member is attached to the frame ,someone shimmed each side with 1/4 in. Plywood and thin conveyor belt. I have a L34 engine to replace flat head,is it necessary to lower the cross member to alight the engine. If so, what should I use.  Thanks for any help.

[athawk11]

No shimming is neccessary here...unless there are other alignment issues created by other modifications, or the original tub mounts/spacers have disintegrated.

If these tub mounts are gone, this may have been done to add space between the tub and the transfer case.  If these items make contact, it can be very noisy while driving.

Tim

[bretto]

I have a L34 engine to replace flat head

Are you stating you are going back to the original power plant and swapping back in a L134 engine?  If so to replace what?
Sometimes shimming stuff here or there, including the tranny mount, was needed in order shoehorn in a non-stock engine.

[Linda]

Iam  going to keep the L134 and the 12 volt system, other than that Iam keeping it stock. I just did not know if I should replace tha wood shims with metal or remove them completely.

[macrisel]

An original body with the original L134 engine should not need any shims.  However.....if someone has put an aftermarket tub on, installed a different motor/tranny/t case, accidently left the tub bracket spacers out or any number of other possible things could cause interference issues.

If possible, post a few photos of your issues and we can probably figure out what the cause may be.

[Linda]

Every thing is a 1951 cj3  The engine had been changed from flat head to an L134 with an 12 volt system. I know the tub has been off because the body was setting on pieces of tire. Possible they weren't thick enough.that could be the reason for lowering the tranny mount cross member.

[athawk11]

Tub mount thicknesses will vary, but is typically 3/16" to 3/8" thick.

Side walls of old tires are a popular choice for use as tub mounts...

[bretto]

So I'm still confused.  In your 1st post you make it sound like you have a replacement L134 engine to be put in.  Now you say it has a L134 in it. 
either way, as stated, not shims needed for a L134/D18/T90 power plant.
FYI, a L134 is a flathead engine to.

[aboyandhisdog]

So I'm still confused.

You are not alone!

[Linda]

Sorry, I'am. A beginner at jeep restoring. My 51 cj3a had the flat head replace with an 4 Cly  hurricane over head engine.i'am going to stay with that engine, when I took the tub off the frame I noticed 1/4 in. Ply wood and a piece of conveyor belt ,where the tranny mount  cross member is bolted to the frame.I wanted to know why it or if it is needed? Thanks for sticking with me.

[athawk11]

Okay, so your current engine is NOT an L-134...and you are planning on staying with the non-original engine.  In that case, the power train may have been lowered to help it all fit better.

Don't be sorry AL.  We all just want to help you with your project ...and we're all easy to confuse.

Tim

[Ryan_M]

Okay, so your current engine is NOT an L-134...and you are planning on staying with the non-original engine.� In that case, the power train may have been lowered to help it all fit better.

I'm curious now. Can you squeeze an F-head into a 3A without cutting a hole in the hood if you shim the transmission crossmember? Interesting approach.

[Linda]

no, the hood has a scoop on it . Would you recommend using a metal or rubber spacer to replace the wood spacer.

[Ryan_M]

no, the hood has a scoop on it . Would you recommend using a metal or rubber spacer to replace the wood spacer.

My first effort would be to try and eliminate the spacer entirely. Figure out why it's there to begin with and see if there's a better way to make things fit. If it does indeed need to be there, I'd go with metal instead of wood.