Transmission toast?
Thread Starter
2nd Gear
Joined: Jul 2005
Posts: 2
Likes: 0
Transmission toast?
I got my –75 vette last fall an its pretty well kept stock condition. As usual it takes a while of driving to get to know condition of things on a "new" car.. Had a little noise from rear end (only at start an more if turning), thought that was the limited slip diff lacking proper additive. Changed oil and put in a bottle of additive, lot less noise.. problem gone I thought. Now I realised that the noise did not only came from the rear end but transmission(TH400). Now I have no drive in "D" when selecting gear from either "P", "N","R" strangely if I select 1 gear it drives. Then after driving a short distance then work trough the gears manually to "D" I have drive even I "D" as long as leave the gear selector in "D". I could then stop and go with no sign of slippage, this works fin until I go back either to "N" ,"P" or R. Then it needs same procedure with starting with first gear selected to get the trans to hook up again. Filter and fluid just changed but without improvement, yes I guess the previous owner/s should have done that a lot sooner. It was little messy but no sign of major breakdown or severely glogged filter.
Forward clutch package gone (take the thing out for overhaul) or could it be something simpler?
Forward clutch package gone (take the thing out for overhaul) or could it be something simpler?
Le Mans Master
Joined: Jun 2002
Posts: 8,339
Likes: 24
From: I can walk to MA
Sounds like a leaky seal or stuck valve in the valve body.
I'm no expert, but I did rebuild my TH400 a few years back.
IMO: If the clutches are gone (worn), it will always slip.
I would suggest the Haynes manual on TH350/400/2004R
It will have a troubleshooting guide and it also has tons of pictures.
Worst case - rebuild it. My B+M TransKit was under $200 and
replaced everything but the bronze bushings (sold separately).
Good Luck
I'm no expert, but I did rebuild my TH400 a few years back.
IMO: If the clutches are gone (worn), it will always slip.
I would suggest the Haynes manual on TH350/400/2004R
It will have a troubleshooting guide and it also has tons of pictures.
Worst case - rebuild it. My B+M TransKit was under $200 and
replaced everything but the bronze bushings (sold separately).
Good Luck
Drifting
Joined: Nov 2001
Posts: 1,469
Likes: 6
From: 68 427 4.11s Roadster
Theres a simple check to do first but I don't think this is it.
Take the vacuum line off the vacuum modulator, big can on the right side of tranny. Slide a q-tip in it- should be dry. Any tranny fluid in the hose or the q-tip means the vacuum modulator needs to be changed.
Hopefully this is what the prob is since its cheap and easy
Take the vacuum line off the vacuum modulator, big can on the right side of tranny. Slide a q-tip in it- should be dry. Any tranny fluid in the hose or the q-tip means the vacuum modulator needs to be changed.
Hopefully this is what the prob is since its cheap and easy
