Hey guys, well I finally got my 69 chevelle back on the road, but with a problem. When its just me in the car all is fine, when its me and a passenger the driveshaft hits the tunnel. Actually its the front yoke of the driveshaft that hits and makes a terrible racket. I just replaced my lowers with jegster(ssm) lift bars, edelbrock adjustable uppers, moroso trick springs, and just some auto zone shocks for temporary use. The car is a 468 with a TH350 behind it and a 12 bolt with 3.73s. This problem existed previously, but the past owners fixed it with air shocks. The air shocks are the reason it was down for 6 weeks due to a broken upper shock mount, so I certainly am not dumb enough to put those back on. Any ideas as to why this could be happening, could it be due to past owner using small block front springs with a big block in the car? Any suggestions would be great, the car is fun, but I would like to take my family for a ride sometimes too and that can't happen right now.
Thanks guys, I appreciate your advice Jeff

Is it possable that you have the wrong tranny mount , or the crossmember is a little bent??

The tranny mount was just replaced with a poly urethane from energy suspension and the cross member looks good, I also should mention I use moroso solid engine mounts. As for the tranny mount, don't all chevy th350s use the same mount?
Thanks for the suggestions Jeff

short shaft/tail housing transmission?

I have the exact same problem on my 68, it only hits when I have a passenger. I too used a poly trans mount. I htink this type of mount is a little taller than a standard one, and that pushed the tailshaft up towards the floor a little. I think the only cure is to lower the trans mount, or use a smaller front u-joint (with smaller yoke). It'd be hard, but you could also modify the tunnel. The last thing, if the body mounts are worn, wouldn't they allow the body to sit a little lower and possibly get too close to the trans?

I'd start by trying a stock type rubber trans mount. Make sure you fix it though, that beating WILL cause damage if it happens too much.... ask my tailhousing why it suddenly fell to pieces..... ;) Good luck!

chris

Forgive me as I'm trying to understrand your problem. It seems to me that regardless of the rear suspension that the tranny and front yoke are always in a fixed position relative to the floor of the car. Is it possible that the floor of the car is weak from rust or fatigue of some sort and is sagging into the yoke when more than one person sits in it?

Rod

If you have carpet on the inside, you won't even notice if you were to beat the clearance you need in with a BFH. Worked for me...

Originally posted by quikss:
As for the tranny mount, don't all chevy th350s use the same mount?
Nope. Found this out the hard way. Energy Suspension makes a tall and short one for TH350's. I bought the tall one and it did the same exact thing yours is doing. I threw a stock rubber mount back in........all is well.

I have a '69 convert, sits 1.5" lower that stock. I've had 4 LARGE (don't tell them I said that) people in mine, no problem. Well it did bottom hit the rubber bumpers a couple of times..... but no driveshaft interference.

Thanks to everyone, I questioned whether a rubber mount would be shorter, as that would be an easy and logical fix. Also I agree that it is possible that the body mounts maybe sagging, because of the extra weight it hits. As I see it, its not a driveline problem because it only happens when there is extra weight in the car, so that would make it a tranny mount or body problem.I sure do appreciate everyones help, this has got to be the greatest group of guys(and gals) on the net. Thank you, Jeff