JIMMY92w

1992 Jimmy. Four door, 4.3L CPI, Automatic (700r4, 4L60)

Last month I replaced my failing transmission with a re-manufactured from Bumper To Bumper. After driving it now for a month and becoming familiar with its operation, this reman. is starting to pi$$ me of.

First of, and worst of, it does not down shift most of the time, especially when running at speeds over 50 kph.

If I'm running 20 kph, and slam the gas it will usually down shift and start roaring. But If I'm at 50 going up a hill and slam it, it will start gaining speed slowly, but will not down shift.

YES, the TV cable had been adjusted many times.

Also, when slowing down the down shift either from 3rd to 2nd or 2nd to 1st is very noticeable. It feels like it just drops in to the next lowest gear, just clunk, but with no abnormal sound.

Fluids are fresh and full, bright red, and no smell.

Is there a break-in period for these things?

THANKS

Chris Stewart

Sounds like the torque converter clutch is not disengaging. Cruising 50mph on a level road, take your foot off the throttle then re-apply throttle...does the trans feel like it up shifted or the torque converter clutch engage?

MT-2500

No break-in period.
Shifting is controled by valve body and governor and some adjustment on YV cable.

I think they still have the governor on side that affects up shift and maybe downshift.
You might want to check it out.

Did you flush the rad transmission cooler when you put it in?
Contact who ever rebuilt it.
They may be able to help.
Some rebuilders change the valve body around for firm shifts and stuff like that.

On the TV cable can you feel two different pressure pulls on it.
Like about 3/4 way down more pressure to pull it?

On a normal take off what are the up shift MPH speeds?
1-2 2-3 and 3-4 and is lockup working good?

Is engine running good?

__________________
Remember proper testing gives us the answer to many problems.
MT

JIMMY92w

When cruising 50mph on a level road and I take my foot off the throttle then re-apply throttle... it feels like it goes in neutral, then when I apply the gas it feels like it goes back into gear.

Yes the transmission has a Governor, but being under warranty I don't think I should pull it out, and check it out.

This transmission, in no ways, has firm shifts, they're long and sluggish.

Yes the radiator was flushed.

Normal shifts at average driving speeds (MPH)
1-2 - 18 MPH
2-3 - 32 MPH
3-4 - 61 MPH

Resistance felt when pulling the TV cable is light at first, then stiff through the last half.

I have NO idea what lock up feels like, or when it locks.

Alright, this test drive I road her very hard and determined the it will not down shift from 4th to 3rd.

I did have 2 service codes 42 & 44, and I think the code 42 was due to not reconnecting the timing wire, after timing the engine. I'm still working to try to fix/clear these codes.

thanks

MT-2500

Up shift speed is is good so governor should be working.
If full of fluid and fluid level is good hot idle.
And If it is droping out of gear you have a onyernial problem .
It is time to call/take it back to rebuilder and find out how good the warranty is.
Good luck And let us know how it goes.
MT

__________________
Remember proper testing gives us the answer to many problems.
MT

Chris Stewart

DTC44, Lean Exhaust Indicated....low fuel pressure, low power, makes the trans look crummy too.
Need 55 to 60 psi that'll hold for a few minutes after cutting the keyswitch off.
Pressure tester available at most auto parts stores and has been seen at a good price at Harbor Freight.



Think this would help the power?


42 cylinder Russian boat motor.

Watch it here in a German tractor puller.

http://video.google.com/videoplay?do...lindex=3&hl=en

JIMMY92w

Hey Chris, you bring that baby over to my house and drop her in my truck any time you like

Last night when I test road my truck, I was super hard on her, compared to how I normally drive, and by hard I mean slamming the peddle to the floor every chance I had, almost causing the engine and tranny to pop out, and the rubber to tear off my rims, seemed to make her more peppy today!

Almost like the computer learned my new driving style and anticipated me to slam the peddle. But it still feels like it drops into 1st gear from a down shift from 2nd, almost like down shifting a standard without using the clutch.

I've been meaning to test that fuel pump , because this is the second year in a row that the pump died. So if I can catch it this time maybe I can time its death before the warranty runs out.

QUESTION: When I rolled my truck last month, and it was sitting on its roof for 8 hours, could sediment from the tank have entered the fuel delivery system and restricted gas flow?

MT-2500: "And If it is dropping out of gear you have a onyernial problem " Your search - ONYERNIAL - did not match any documents. (Google)

THANKS

MT-2500

Sorry about that.
My key board messed up again.
Should have been internal problem.
MT

__________________
Remember proper testing gives us the answer to many problems.
MT

Chris Stewart

That's what a fuel pressure check will show. Low pressure can be pump or filter and after the roll, it could very well be a clogged fuel filter.

JIMMY92w

I'm reading in this HAYNES GM Automatic Transmission Overhaul TechBook on:

How to conduct a road test.

It says: "To test for part throttle downshift, accelerate the vehicle to approximately 45-mph in high gear, then quickly depress the accelerator half way. The transmission should only downshift one gear. Repeat the procedure, opening the throttle fully, to test the full throttle downshift. Depending on the speed and transmission model, the transmission may downshift one or two gears."

When I do this test, am I to fully release the gas peddle once at 45-mph and then quickly press it half or full throttle?
If the transmission does not down shift in either case does this mean miss adjustment, defective parts or something else.

If I can pinpoint a definite problem I will not hesitate to get a replacement transmission under warranty.

THANKS AGAIN.

Chris Stewart

Nope, you'll be cruising at 45mph to perform the tests.

Have you checked the fuel pressure?

MT-2500

If you have adjusted the TV cable and it is working ok and engine is running good.
I would.
And The TV cable has full pull on wide open throttle.
Call the rebuilder and tell them the problem and ask them what test you should run on it or what direction to take on it.
Good luck
MT

__________________
Remember proper testing gives us the answer to many problems.
MT

Slow_Ride

That video was awesome!!!!!!!!! I live in Arizona. Any idea where the nearest tractor pull is???


42 cylinder Russian boat motor.

Watch it here in a German tractor puller.

http://video.google.com/videoplay?do...lindex=3&hl=en[/quote]