I have a 2001 XJ8 with 113K miles on it. Tranny had never been serviced. Recently I noticed the transmission acting strange. Everything seemed perfect whenever it was cold but after about a 10 minute warm up things changed.


The first symptom I noticed was that the car acted like the brakes were on when backing up. It wouldn't roll very fast in idle. But in drive it would move forward normally.


Second symptom is it shifting harder. Probably not noticeable to most people but usually the tranny shifts so smooth you can barely feel it. Shifts perfectly smooth when cold.


So then I finally changed the fluid and filter that I had been putting off for years. Hoped this would cure the problem but of course it didn't.


Third symptom I noticed is the car moving forward a little in Park and Neutral. Of course in Park it only moves a few inches. I first noticed this when starting the car from dead cold....so unlike the other symptoms this happens cold. It only does this about half the time. On level ground you can actually move the car in Neutral at a very slow rate of speed.


So, I've done a little reading and learned about the pressure control valve failing but my car doesn't have the main symptom for this. When you put the car in gear from park it engages instantly. So maybe this valve is still good.


I have stopped driving the car in case the problem is something in the valve body and might cause more damage.


Thanks in advance to everyone that helps me diagnose this.


Jordan

 

Anybody? Where are all the tranny experts out there?

 

Do you have any fault lights or codes showing up on the OBD2 reader?


The transmission is used by BMW and Mercedes so a lot of shops will work on it
for a reasonable price. I had mine overhauled for around $2,400 installed. They seem to last roughly 80,000 to 120,000 miles.


Get an exchange valve body with new solenoids and that will give you great piece of mind.

 

The forward ('A' drum) could be cracking at the snap ring and the frictions/steels are pressing against the drum in line with it.

When it fails COMPLETELY you will get the high revving and then the SLAM into 'limp mode'.

I can usually do a drum replacement in 8 to 10 hours with the normal interruptions during the day.

I have been replacing them more often lately. I even keep a spare in stock.

You can even leave the new fluid/filter in place if you tip the gearbox on it's tail and replace the parts that way. You will lose a little from the torque converter but that can be measured and replaced to maintain the correct fluid level.

bob gauff

 

No codes at all yet. So you think the A-Drum has already cracked? Is this what is causing the car to move when in N? I was hoping for a valve body problem.

 

Motorcarman, is this why the car will actually move forward a couple inches while I'm turning the car over to crank it? I'm not the expert you are but it seems to me that this symptom has nothing to do with fluid pressure since there wouldn't be any pressure at this point.

 

No codes at all............... in what module?

Can you read TCM codes???? There might not be DTCs in the ECM.

Your problem could be torque converter related??? I don't know.

I would drive it until it fails but then again I have 2 spare gearboxes with new 'A'drums in my shop just waiting..............

bob gauff

 

No faults on the dash at all. No, I can't read TCM codes but I have someone that can. Could I have a TCM code even if I haven't had any faults come up on the dash?

 

I have been driving the car lately in sport mode. Tranny seems to shift perfectly now. The only symptoms now seem to be that the car moves slightly forward when it is in Park or Neutral while the engine is running. About half the time when I go to crank the car as soon as the engine turns over from the starter you can feel the car move forward a couple inches. The car seems to always slightly move forward in Neutral now as if it were rolling down a slight hill. The only other symptom is that it doesn't move in Reverse normally. It acts as if the parking brake is on slightly. It only does this after it is very warm. It backs up fine it just doesn't move backwards in idle as fast as it does in Drive.

 

That rolling forward during cranking is very strange. Like the torque converter is locked up.

 

I know, it is quite strange. It does seem kind of like the torque converter is partially locked up. But, I'm not sure if that is possible. Isn't it either locked or not locked? If it were locked up the engine would stall whenever the car was stopped in gear. Like pulling up to a stop sign in a stick shift and forgetting to push the clutch in.


I'm going to see if there are any TCM codes but I haven't ever seen any transmission faults on the dash so I'm thinking it won't have any codes.

 

Could it be that the gear shift cable is out of adjustment (weblink thread - post# 6)?

https://www.jaguarforums.com/forum/x...witches-87638/

Jim Lombardi

 

IMO your console shifter cable has stretched. If the car is rolling or making a clicking sound in park. The adjustment is rather easy to do but it is very precise. If done wrong your overdrive will not down shift and it will be stuck in the upper gear or R will not be in the correct channel. Mark the original position so you know where you started. It's easier to do if you remove the center console itself.

 

Also go to euro toyzdotc and buy a transmission dipstick. Let it idle for 15 minutes and take it for a boot, go through all the gears stationary on level surface. The TA fill on passenger side/USA. Just after the 90 degree intake bend. In all likely hood hood you will be down anywhere from 1-5 quarts. Make sure to use the correct AT fluid and also make sure one if the quarts is AT treatment from Lucas.

 

Do yourself a favor and check the adjustment of your shifter cable first.

 

I had the TCM codes checked. No codes of any kind.

 

Thanks to everyone that has helped me with this so far. In regards to the possibility of the shifter being out of adjustment....without taking the console apart and actually doing the adjustment procedure, I think I can most likely eliminate that as the problem. The shifter works exactly like it always has. It goes into park with no clicking and goes into every position just like it is supposed to. When I have the car running and in "N" and it is moving slightly forward moving the gearshift slightly out of the detent toward "R" doesn't stop or change the problem.

 

I'm thinking about going ahead and installing a good rebuilt valve body and then just driving it till it fails. Maybe I will be lucky. Where is the best place to get a good valve body?

 

Sunbelt is one supplier, but I have no experience with them.

AW55-50, O1M, JF506E, 5R55E, 09G Valve Body Replacement

 

When the same symptoms happened on the borg warner trans fitted to earlier vehicles, it was the forward drum diaphragm, and a broken bit holding tension on the clutch (very common). The vehicles used to permanently be in second gear(slipping) - Hence creep in neutral and park, and weird reverse - I would suggest you have a mechanical problem, relating to your forward drum, not releasing correctly. Good luck -