02 has no 4th gear

[93pb]

Well In drive I am running about 3000rpms @ 80 and when I shift into 3rd no kickdown so it seems I have no 4th gear.

Is this the dreaded shift solenoid? I have no check engine light.

Marc

[baron1701]

Check Your Throttle Position Sensor And Your Egr Valve. If Either Is Faulty It May Prevent You From Using Overdrive. I Had The Same Problem.

[93pb]

Originally Posted by baron1701

Check Your Throttle Position Sensor And Your Egr Valve. If Either Is Faulty It May Prevent You From Using Overdrive. I Had The Same Problem.

Okay thanks but wouldn't I have a ses light if one of these were bad?

[maxwedge]

May not set a code right away, to confirm any diagnosis this needs to be scanned on trans function scanner for 4th gear solenoid commands and slippage /gear ratio errors, I doubt if the tps would cause the loss of 4th only.

[93pb]

Okay so today I attempted to change the shift solenoids. I take the pan off and no valve body? Must be on the side pan! No way I am attempting that !
I have the 4t65E with the 3.5L V6
So I change the fluid and filter (needed it anyways).
So my latest question is what should I see for rpms at 60mph with this car.
I can't really tell if it is shifting to 4th or not it sometimes seems like it is but the car shifts so smooth it is really tough to feel the shifts.

I am turning 2500rpms at 60 mph in (D) and roughly 2800 rpms @70mph.
I still get 24 mpg with the car just seems high to me as far as rpms go.

Marc

[BNaylor]

Check the SPID label on the back of the trunk lid or spare tire cover and look for GM RPO code MN3 which is a 4T65E autotransaxle. The 4Ls are typically for the V8 Auroras.

You should see the drop in rpms when it shifts into 4th (OD). Have you tried upshifting manually?

4T65E can fail to shift to 4th (OD) due to a valve body related problem (3-4) shift solenoid or a mechanical problem such as a bad spline. Another problem is it is shifting into 4th but the torque convertor is not locking. You can see the TCC lock by watching the tach drop at speeds above 45 mph.

Any valve body work in these trannies is not typically DIY since the valve body and solenoids are located under the side cover assembly.

[93pb]

Well I took the egr valve off today and started the car while looking at the valve. While cold and at idle the valve did not move. I would think the pintle would actuate so my guess is it is a bad.

This is a digital valve as well, looked it up on Napa's site and they want $154 for it!

[maxwedge]

Originally Posted by 93pb

Well I took the egr valve off today and started the car while looking at the valve. While cold and at idle the valve did not move. I would think the pintle would actuate so my guess is it is a bad.

This is a digital valve as well, looked it up on Napa's site and they want $154 for it!

You will not see any pintle actuation commanded by the pcm unless the car is warmed up and driving at a certain load/speed. The pcm modulates the egr based on programming, with a wiring diagram you can ground certain wires to the egr and the engine would stumble to confirm operation.

[93pb]

Does anyone know about how much a full rebuild for the transmission on these cars will run?
I changed the egr valve and still no 4th gear, when I changed the fluid and filter the old fluid had allot of brass filings in it . Looked like I was panning for gold!!

So my gut is telling me the tranny is done! At only 80k doesn't speak very well of GM!
I am thinking of taking it to Cottman to have repaired , it isn't my daily driver so I have plenty of time.
I may just sell it after the tranny rebuild as the car just sits for the most part.

Suppose I should consider myself lucky been about 20 years since I had a car that needed a transmission, and that was another gm product too.

[BNaylor]

Average cost for rebuild on a 4T65E is around $2K. Remanufactured for under $1K but there is the cost of installation. The problems you are having is common for that model autotransaxle even at your mileage. Good luck.

[93pb]

Just to follow up I just had my 4t65e tranny fully rebuilt and installed and it cost $2200.00.

This included the chains and the new cookie cutter shaft which has a spline on it for 4th gear which was totally stripped out, as well as new bearings etc.

Tranny shop said it is a common issue with these tranny's to strip out the splined shaft and it is a design flaw as far as they are concerned.


Marc

[maxwedge]

This thread is way too old to continue.