The Stovebolt Site Forums The Shop Area Engine Shop 72 4 speed trans questions

I came across a 4 speed trans with a granny gear out of a 72 truck for $100, the trans has four bolts to meet up with the bellhousing. I have a 235 in my 53 truck with a SM420 4 speed on the floor (no cyncros SP). I am in the process of changing the rear end and loosing the closed driveline. I know I will have to have a drive shaft made or find one the right length. Other than that, it appears this should just bolt up and I should be in good shape. Is this true? Clutch problems/issues, or anything else that I need to know about the swap.

Lastly, if I decide to go to a V8 in the future(keep that quiet), will it work well with the V8.

Any information or imput would be great.

Check the diameter of the front bearing coller & make shure it is the same where it fits in the bell housing. There are some variations there. Some have the E-brake on the back of the trans. If that fits it should work. The v-8 also will work using a matching bell housing. This is a tough trans. It should make a worthwhile swap.They are difficult to o-haul though but some repairs can be made without a complete teardown.

Wrenchbender Ret.

Thanks for the info. I will measure the bell housing opening when I pull the old trans.

How hard is it to find another bell housing that matches, or can the existing bell be opened more if need be?

Thanks,

Dan

That tranny is likely to be a CH-465 just for the record. They were used all the way up through the 60 series.

Dan, are you saying that the SM420 that is in your truck now isn't synchronised? If it's a '53 tranny, it should be sycnchro (except 1st gear).

Thanks guys,

As usual, you all provide and great information and insight. I sent you some email questions directly.

Xram53, I haven't had the truck running but, I believe the drivetrain is the original since it is the sealed driveline. I also haven't had a chance to clean all the crud off of the trans to get the numbers for positive identificaiton. I hope to get to that in the next week or so.

I will let you know what I come up with.

Thanks again to everyone.

If your tranny has reverse to the left and down, it is the SM420. I actually prefer this to the later SM465, reverse to the right and down. The 420 has the advantage of being a faster shifting box, but both are durable boxes. For some general info go to http://www.novak-adapt.com/knowledge/knowledge_gateway.htm

The bell housing will need machined to work, but it's minor. You could use a bell from a 68-72, but the starter and cluth mounts are different.