1992 Bravada Tranny Problems?

[Josh Smith]

Hello,

After it began warming up around here I started to notice a whining noise coming from my transmission under high RPM, or when accelerating. It was faint and I wasn't 100% sure it actually was the transmission as it started after the engine warmed up (above 200deg).

Today I was driving to college and when it should have begun whining, it instead lowered its power output - hard to accelerate in other words.

Thing is, the engine didn't accelerate any faster than the transmission.

I'm thinking perhaps the fuel pump is connected to the oil sending unit in this vehicle. It only starts doing this after it warms up all the way. When it's cold it does just fine.

I figure on starting with an oil change and a tranmission fluid and filter change as it needs both.

Anything else I should know about? This should be a 4L60E transmission.

Thanks,

Josh <><

[Josh Smith]

Scratch the year; it's a '93. Hit the wrong key. Sorry!

Josh <><

[maxwedge]

Are you sure it is the trans and not a noisey fuel pump, is the fluid burnt?

[ericn1300]

doesn't sound like a tranny problem. transmissons usually slip when cold and work better when warmed up.

[Josh Smith]

Gents,

I determined it's not the tranny. I do not do my own oil changes or tranny filter changes any longer - I stick to diagnostics - but a friend of mine owns a oil changing shop. While he was changing the oil I got to poking around, and it seems the catalytic converter was damaged once in the past, partially blocking it. It looks like it ran too rich before the problem was caught.

Soooo.... I'm looking at a new cat. Likely will just take the dang thing off as it's one of those stubby ones.

Fluid was good and what we saw in the pan was what I would expect a tranny with 50,000 miles on it to have, not 189k.

I'm starting to wonder if this has had a new tranny and motor installed as the motor specs out to waaaaay less that what the odometer says it has.

Thanks,

Josh <><

[Chris Stewart]

After the first trans fluid & filter change, a trans doesn't wear much since all the rough spots have worn smooth. Seal conditioners in the fluid help keep the seals in good shape which keeps the clutch packs tight when under pressure. 190k on my '92 w/4L60.

The GM engineers fixd that...the 4L60E electronic trans with the electric shift solenoids have given me trouble $$$.

[ericn1300]

Originally Posted by Josh Smith

Soooo.... I'm looking at a new cat. Likely will just take the dang thing off as it's one of those stubby ones.

Fluid was good and what we saw in the pan was what I would expect a tranny with 50,000 miles on it to have, not 189k.

I'm starting to wonder if this has had a new tranny and motor installed as the motor specs out to waaaaay less that what the odometer says it has.<><

Chris is right, a fluid change will help the tranny immeasuearably and the engine should have compression and good main bearings for 300k, just the top end you need to look out for.

As far as the cat, it is a violation of federal law to eliminate it or replace it with a less efficient unit. check out the blazer perfomance forum for a good replacement unit: http://www.automotiveforums.com/vbul...lay.php?f=2071

[Josh Smith]

As far as the cat, it is a violation of federal law to eliminate it or replace it with a less efficient unit. check out the blazer perfomance forum for a good replacement unit: http://www.automotiveforums.com/vbul...lay.php?f=2071

As a professional automotive technician I am very familiar with smog regulations - I have to be.

As we were taught in law enforcement school however, it's only illegal if you are caught. The EPA would not have probably cause to strip my exhaust to check for a hollowed out catalytic converter.

Sooo, as I said, it's only illegal if you're caught. Seriously. I was going to be a police officer and we were taught this while I was pursuing my degree.

It is much more likely however that I will put a flowmaster unit on it and match it with a cold air intake and K&N filter since I tow with it.

Josh <><

[Chris Stewart]

Originally Posted by Josh Smith

Gents,



Fluid was good and what we saw in the pan was what I would expect a tranny with 50,000 miles on it to have, not 189k.

I'm starting to wonder if this has had a new tranny and motor installed as the motor specs out to waaaaay less that what the odometer says it has.

Thanks,

Josh <><

Somebody might have changed the trans. fluid the first time before you got it then it just doesn't "dirty-up" any more except maybe get that varnish smell.
I pull 3 qts. out and add 3 qts. every summer on mine...the other cars too.

With so many semi-synthetic oils being used now, most well kept motors should still look new inside after many miles.