I recently picked up a 98 Cherokee. When I bought it the check engine light was on and the previous owner said it was for o2 sensor. As it turns out it's for the b shift solenoid. Sometimes it's doesn't downshift but shifts fine manually. Before anything I figured o would drain the pan and see what the fluid looked like.

Not great. So if I drive around for 30 minutes would I get enough mixing to drain it again?

This is just the first attempt. I'm going to hook up to the tps later today and if I can find a pin out check the resistance of the solenoids. Obviously I need to cycle through and get some new fluid in there anyways.

 

15 mins is good enough.. Just keep doing the drain and refill until fluid starts too look a nice clean red.

 

Thanks. That is the plan. I'm hoping that everything is just gummed up and this fixes one of my problems...

 

Why not do the redneck flush??

Disconnect return line into tranny, put a piece of clear hose over it and run that into a bucket with capacity markings. Crank the jeep and let the the fluid pump into the bucket until you see an air pocket. Shut off the jeep, add the amount of fluid that was pumped out and repeat the process. Always only add what gets pumped out so you don't overfill. This way you get minimal mixing of old and new fluid. On the run after you add fluid the first time I like to shift the tranny through all the positions holding in each gear for 10 seconds or so to help flush everything.

Should take you about 8qts to complete.

 

I have never done it that way before. Good suggestion. If I have to go after the solenoids maybe I'll start out that way. I did three drain and fills today I'll see if that makes a difference.

 

See my sig, #3.

 

Can't see sigs on the mobile. I will have to check from a computer a bit later.

 

Well Now I just need to know who wants to be helper #1 and helper #2.


Drove about 200 miles this last weekend and trans still will not downshift to first. I didn't check out the TPS yet, but I'm almost 100% I'll be changing the solenoids. I drained and flushed 3 times prior to this weekend. It isn't perfect, but it is much better then it was.

 

if clutch material is washed, it isn't going to matter how much you flush-n-fill... that stuff got dark from something and it wasn't rainwater. transmissions are at their best when they are sealed. a matter of fact, many NEW transmissions have been engineered following the advice given by many a transmission builder for over a generation: "transmissions are contaminated 99% of the time by bad servicing practices".

all that said- the redneck flush i'm familiar with (and have done countless times) is similar to the above but with one big difference: disconnect the cooler line, point into bucket, pop the seals on as many quarts as the transmission can hold + three to four more- line them up for easy reach... fire up engine in neutral and let her run and while pouring new juice in it... when the juice coming out is as bright as what's going in, kill the engine.... remove cooler, clear it out... refill to full line.

 

Actually, the solenoids resistance checks are not accomplished at the TPS.


Refer to this TCM pinout and test procedures. You'll find the pin cavities in the TCM connector to take the resistance checks.



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It looked like a bad tps could cause some shifting issues. I was going to check voltage there.

I was also going to check solenoid resistance at the TCM as well. Thank you for posting that. Saves me from trying to find it.

 

well finally got around to checking some things.

Checked the tps at center wire idle is .8V and full open is 4V. Good

I checked my solenoid resistance and everything was good. Sometimes the jeep runs fine until the trans heats up. I got approximately 15 ohms on all three. After about 20 minutes of driving it wasn't shifting right again. So I pulled over and rechecked my resistance. B solenoid was open.

Looks like I will be ordering one of the kits that comes with all three and replacing maybe next weekend. Maybe I will get some diff gaskets as well and have a little party draining and refilling everything.