Trans issue: how bad is it

[-Wip-]

So I had my typhoon out for a cruise night last night. 49k miles on it, all stock. I downshifted from 3rd to 2nd and a low speed and felt a huge "bang" like I just hit a giant pothole! Wasn't sure what happened so I looked around the truck, no problems. Kept on driving, seemed to shift a bit less firm but later on in the night, that was normal again. BUT, I did notice that when the truck downshifts on its own, or manually, it doesn't carry the rpms down. It drops the rpms right to idle.. Any thoughts on what I'm looking at before I pop this trans out?? My knowledge on transmissions isn't the greatest, so any input is appreciated! Thanks in advance!!

 

[Slyclone]

Re: Trans issue: how bad is it

Yo, since you lowered the truck or slammed it? Could it be the front prop shaft slamming or your drive shaft?

I know when vehicle lowered the drive bone angles change and can heat them up and wear them out.

Could be something along them lines. I remember you said the truck was low??

 

[2500avalanche]

Re: Trans issue: how bad is it

I dont know if this helps, but change the ujoints in teh drive shaft/prop shaft. I know mine always had a bang when changing gears. Changed the ujoints, and the bang went away. It shifts very smooth now. Also, have you checked your fluid?

 

[-Wip-]

Re: Trans issue: how bad is it

Thanks joe,, its definitely something with the trans, not the suspension. Only because I noticed it wasn't holding rpms on downshifts anymore and it's never done that before. It had a couple delays, then real hard 1st to 2nd shifts as well.. Thanks Avalanche, I checked the fluid this morning and seemed to have way too much. Buddy told me last night the torque converter is probably pouring fluid into the pan

 

[Quickstop [UK]]

Re: Trans issue: how bad is it

I'm probably wrong but I wonder if an overrun clutch or sprag has blow up inside? If you downshift, the sprag should be holding and it will drive the RPM somewhat but if it has failed then when the drum decelerates, the sprag isn't holding and so when ttrans changes gear, there is no drive to the drum or back through to the converter. I'd expect the lack of load to mean that the RPMs would climb though

When do you plan to take it out? What trans is in it?