Chevy Nova Forum banner

Transmission mount not lining up with crossmember

10K views 9 replies 4 participants last post by  Seattle_Mike 
#1 ·
I'm installing a Heidt's 4 link in my 62. My car has a 355 sbc with a Tremec 3550 5 speed. The front end in my car is from Chassis Works so I know the engine is centered in the mounts/car but the trans tail shaft is definitely closer to the passenger's side. The new mount is off by 5/8". I looked at the cross member I removed and the holes are not in the center. I'm wondering if the Tremec mounting location is not on the center line of the trans and requires an offset mount. Of course I tried prying the tail shaft over but it won't move that far. Anybody seen this one before?

In this pic, the side to side is off. The cross member is slid back to show how much it's misaligned.


This is the old cross member. Center is 5". Hard to tell from the picture but you can see the mounting holes are not based off of center line.
 
See less See more
3
#2 ·
Okay, some stupid questions first. Do you have the cross member facing the right way? I'm sure you do, but without the instructions, I had to ask. Next, are there elongated holes (probably not or you would have done that) that allow the CM to move sideways. Is the CM upside down and spun 180? Maybe it's the picture of it in the car looking at the tailshaft that's leading me that way. It looks like the CM will be in the way of the tailpipes and should be turned over so it angles up rather than down.

Thanks for doing this with pictures, they really help.
 
#3 · (Edited)
You are correct sir...early Nova's have the entire drivetrain offset to the passenger side. You aren't halucinating. For some reason, a few of the aftermarket clip vendors never accounted for it as they just assumed that the drivetrain is centered in the chassis. Chassisworks clip keeps the drivetrain all correctly aligned in the stock location which is NOT centered. The problem is if you now offset your transmission mount so it's centered, the rearend is out of line with the rest of the drivetrain so it should be fixed also. Some people ignore the fact that the drivetrain is not aligned but to me, spending all the time and money to do one of these and end up with zig-zag drivetrain alignment is crazy. Since you are using a Chassisworks clip, if you are using an aftermarket crossmember, it's probably centered so therefore you are seeing a misalignment.
 
#4 ·
You are correct sir...early Nova's have the entire drivetrain offset to the passenger side (including rearend). You aren't halucinating. For some reason, a few of the aftermarket clip vendors never accounted for it as they just assumed that the drivetrain is centered in the chassis. Chassisworks clip keeps the drivetrain all correctly aligned in the stock location. The problem is if you now offset your transmission mount so it's centered, the rearend is out of line with the rest of the drivetrain so it should be fixed also. Some people ignore the fact that the drivetrain is not aligned but to me, spending all the time and money to do one of these and end up with zig-zag drivetrain alignment is crazy.
 
#6 ·
Thanks Pete and Mike. I spoke with Chassis Works today and they verified that the engine/trans is 1/2" closer on the passenger side just like the factory front end was. I asked why other vendor's clips would center the engine and he said that they must think people only race their cars. Huh? Didn't make since to me either. I think the factory offset the engine just to frustrate me 50 years later.:mad: I'm sure I'm just running into the "normal" stuff when trying to use aftermartket "bolt-on" performance parts. I hate to do it, but the Heidt's CM is getting returned. The CM I had works fine but I thought I would change it because the Heidt's sub frame connectors have tabs welded on to accommodate using their adjustable CM. I could easily overcome the offset issue by drilling new holes in their CM but theirs is so low, there is no way you can run 3" pipe out of the collectors and clear the stupid thing. I'm going to cut away the plates from the SF connectors cause they will be in the way and reuse my old mount. BTW, Heidt's was completely uninterested in my problems.:(




This picture shows old CM next to new. See the offset to the right on the old CM? Top of pic is towards the front of car.
 
#7 ·
Oh yeah, I forgot. Mike, I 'm installing a ford 9" as well and I understand the pinion is offset. Even more zig zag? I asked if the new narrowed housing would be centered having one long and one shorter axle/tube and Heidts said no. Won't be a problem and drive shaft won't hit the tunnel. I guess I'll have to wait and see. The 3rd member I received had the wrong ratio (they screwed up) installed so I didn't open the box to trial fit. Still waiting for the correct 3rd member.
 
#8 ·
Welcome to the world of old stuff. There are lots of hidden gotchas in old cars. If they haven't rusted, twisted or been wrecked, they droop from old age. But then, so do I. There is a lot of "interpolation" involved in doing custom work, and reworking your car like you are definitely comes under custom, taking should work to will work sometimes takes modification. It wouldn't be that hard to fabricate a CM yourself really. The two tough points would be getting the tubing bent correctly and getting the slots cut for the bolt holes. Check around for someone with a pipe bender - I got mine from Harbor Freight for 100 bucks - and any machine shop can cut the slots.
 
#9 ·
You're right Pete, fabricating a CM should be easy. Unfortunately, I don't possess a welder, welding skills or scrap metal lying around. Just rejoined the car scene so I haven't made any friends with tools/skills I need yet. At this point, I have to source what I need. I've been searching the web and looking at all kinds of CMs and then I thought about the TCI 4 link again. Looking at their kit vs. Heidt's, the sub frame connectors bolt/weld up the same way. TCI's cross member looks like it bolts on just like Heidt's. Difference is TCI CM is arched up higher and should clear the exhaust no problem. I will call them tomorrow and ask for tech advise. I'm curious also if there CM is centered of offset. Heck of a thing to have to mix and match parts from two competing vendors but what ya gonna do? Wish me luck.
 
#10 ·
I made this crossmember with the offset in the mount. As you can see, it has a drop in the center for the actual mount. This is 3 1/2" oval tubing and clears the crossmember fine. They make the round to oval collector transitions so it's pretty straight forward. These were Chassisworks headers on a BB Chev install.

 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top