|
|
Veteran
Posts: 295
| On my 57 Suburban the trans acts funny. It's got the 325 poly and evidently has the cast iron Torgueflight. I hear they have a pump front and real. What mine does is this. I can fire it up, let it warm a few seconds put into reverse and it clicks into gear right away. I back out whip it around and push Drive and it just sits there. It's gotten worse over the years but now it can take 3 minutes or more before it engages into gear at a dead idle. I've found that a little bit of increased throttle, even 50ish rpms, will make it engage much sooner but I suspect that might not be good for stuff. I found a source for parts but I'd like to have an idea of what might be causing it.
The first thing that came to mind to me was a servo seal ring, possibly one of the pumps weak, possibly the front clutch pack piston seal?
I don't know what the purpose of two pumps is. If I had to guess I'd assume that one pump provides sufficient pressure for low gear and the second one maybe adds pressure for the 1-2, 2-3 upshifts. But, I'm just guessing because I don't know.
Note: once it does click into drive, it doesn't have a problem again (until it sits overnight or longer) and still shifts perfectly. I guess that's why I imagine it possibly being a servo or clutch pack piston seal.
Anyone run into that issue on theirs?
Any ideas on what that sounds like?
If all the parts are available for a rebuild I'll get everything it needs and do it. The issue may be getting pump parts or drums if there's a crack or excessive wear or something more than a kit will come with. On modern TF's the kits don't come with a rear band, of course no bushings and obviously no hard parts. That's my concern about just buying the stuff and pulling it apart for rebuild THEN to find it's a hard part that isn't available.
Thanks,
Wayne |
|
|
|
Board Moderator & Exner Expert 10K+
Posts: 13042
Location: Southern Sweden - Sturkö island | Internal leakage - be careful and avoid revving the Engine. The transmission needs a total teardown and renovation |
|
|
|
Expert
Posts: 3393
Location: Chestertown, NY ( near Lake George) | agreed, no short cut here |
|
|
|
Expert
Posts: 3768
Location: NorCal | Problem has nothing to do with the pumps, the front pump engages both Reverse and forward gears at a standstill when the rear pump isn't providing pressure.
The front clutch is used in all forward gears but not Reverse. Any pressure leakage at the front clutch from worn sealing rings or hardened/shrunk rubber seals will cause delayed engagement. An additive like Trans-X or Lucas can soften the rubber seals and prevent the need for removal. It's cheaper than overhaul so worth a try. |
|
|