I have a 68 buick riviera with a 455 in it. About a month ago my drive shaft tore lose and I had to get a driveshaft from a 66 riviera and swap the yokes and have it rebalanced. Now today it finally gets fixed after a month and seems my timing off and it wont rev past 2000 or go in reverse. Now past experince tells me that tranny is bad but prior to the driveshaft breaking the tranny was fine. What would cause this and should I just go ahead and swap trannys or is it something else like a bad torque converter? Yes after installing driveshaft all fluids were topped up in the transmission. .
No this happened after I had a new driveshaft installed like minutes out of the shop..but before the drive shaft broke the tranny shifted fine.
Does it rev past 2000 in neutral? Im having a hard time connecting what the timing, the car not being able to rev past 2000 or go in reverse has to do with the driveshaft breaking. Its going to be difficult at best for anyone here to come up with a good answer for you without having the car in front of them. I would bring it to a qualified mechanic and have him road test it for you.
Ok I know timing is off..thats a seperate subject. Im assuming transmission is shot so I might as well get a new one and maybe go with a different torque converter for better performance
check and see if the vacuum line cam off the modulator on the trans. i had it happen once.. not the same symptoms but its worth a look.
Do you have forward gears? Will it shift through the gears as before and just no R?. A good hard jar can knock the shifting linkages inside the trans and make stuff act real funny. Last trans I put in my car was stuck in Park even though it was also in D at the same time. Eventually broke the parking paw and took off down the drive while I was under the hood messing with stuff.
A severe exhaust restriction will prevent the engine from revving, This broken drive shaft, did it break at the rear joint and flop around? More information? Did you actually check your timing, or are you guessing?
My thoughts exactly. Many years ago a family I knew had a Electra, about a 72. Had a similar problem, a lot of shade tree mechanics gave opinions why no power, no converter to be stopped up. They finally gave up and was prepping to remove the engine, took a sawzall to the down pipes, for some reason it got started that way and discovered it was fine. Close inspection showed the crossover pipe had collapsed inside where 2 became one, looked good on the outside. Problem solved, and one of those things you don't forget. Mike
I don't understand, why you would have to swap yokes between transmissions. Aren't they both TH400s? Or is it the yoke length? Bruce Roe
Probably yoke diameter. The big cars with the slip joint in the driveline used a 1.688" diameter yoke. The cars that relied on the yoke for the slip joint are 1.875". Devon
So the yoke was bolted to the trans? Otherwise swapping the tail housing would fix the dia. Bruce Roe
What the OP probably meant when he said yoke, was rear flange? There are two rear flanges- an early style and a late. being as how the shaft was from a 66, and the OP has a 68, the flanges could of been different and needed to be swapped to match the rear axle. Just guessing though
The car shifts like it suppose to. Im going to check the fuel filter to see if anything clogging it that could prevent it from going pass 2000..when I punch it, it goes past 3000 but not like before. And yes yoke was wrong. The 68 yoke was shorter while 66 yoke was longer.
