Having repaired the “a drive” in my 2000 xj8 vp, I carefully took my jag out for a two mile test drive in my neighborhood max speed about 30 but silky smooth. I did notice when parking the jag for the day, that it wouldn't go into reverse from drive but after shifting to park it perfectly to reverse all smooth as can be. My next day I plotted a longer drive and hope to also explore the reverse oddity. Backed out of the driveway and off I went, everything as smooth as glass. Then drove up to about 45 and suddenly there was a un solicited downshift to what felt like second when I took my foot off the gas gave it gas and it went back seemingly to normal, the downshift again after a few hundred feet. I slowed to see if I could tell what was happening and when I shifted back from drive to park, the car was still in drive when the shifter was in neutral and reverse, and even in park it seemed engaged even though it will still crank from park and immediately goes back to forward pull against park.

My thought was the linkage was messed up or slipping. I got her off the ground and had a friend work the shifter (engine off) back and fourth every which a way and it clicks into the mechanical gear with perfectly, you can not make it miss shift with the shifter.

I have studied this online for a few weeks trying to gather as much info as possible. The only code I get with my OBD reader is 1722 but I'm not a mechanic and maybe I didn't do the “a drive” replacement properly. I really like the car is had a wonderful paint job, original and great interior and ac and sound but I need to fix it without a huge cash layout. The cars have low market value mainly due to the repair cost of the vehicle, and this one will be a heartbreaker if I have to “essentially give it away”.The clutch plates in the transmission only have about 80000 mile but the fluid was solid black, the inside the case was beautiful and only had to replace a few gaskets and no berings. Clutch plates in the a drive looked new...... Thanks for any advice or help

If I take it to a transmission place for their analysis what type of analyser do I need to be sure they have to get me the proper analysis... Will P

 

To be completely honest, I have no ideas about your issue, but I want to follow this thread.

Best of luck, and I am curious to see what others may have to say!

 

Thanks I appreciate that. I enjoy reading in area that are tangental or enlightening to various task I am entangled with. I hope this will be helpful to other and I didn't find anything on this site like this. My problem is very interesting to me and I hope I with the help of kind eyes can find the solution. Even if I had to send my green girl to salvage or to someone to be parted out, I'd like the peace of mind that I did the right thing. It would kill me to let her go when there was something I might have fixed. I'm sure that is the unspoken sentiment of many who read on this site, even fellow like myself who was a long time lurker and learned so much here. Will P

 

Bcrary3 is there anything I can do get attention to this post, I'm fairly new here and would have thought the odd situation would be interesting to Jag lovers, they not being twarted easily by a difficult situation... Will P

 

Any harsh shifting? Did you do the valve update? Are you 100% sure the trans fluid level is correct?

 

There was no harsh shifting, like when the "a" drive broke, I have not done the valve update, yet. And the fluid level is my next effort, when I put it in I thought I did it correctly but, though it was running I didn't take it though all the gears and though I plugged the hole (it had gotten so hot, I had to plug it until later) and some leaked out but my replacement could have be short. I am going to get someone to stand on the brake and top her up again, remember she's pulling forward in Park and that' kind of scary. I don't have an auto lift.

Thanks for the input, I'll do this asap...... Will P

 

When I filled it, it didn't take but about 8.5 quarts, and I know what it's supposed to hold but though some came out of the torque converter, it looked to be a pint at most. I pray that is what it is, I haven't driven it but three or four miles since the replacement, and no harsh shifts, just the unexpected downshift and the forward in neutral and reverse, of course both highly unexpected. I was looking at doing this as an adventure, sorta, and I might have selected a beginner mountain. Will P

 

I might study it a bit to see if I can rig me a all four wheels off the ground way to fill it, I'd feel much safer, do you think that would be better... Will P

 

I would see if there is a shop that you can rent a bay at a shop with a rotary lift.

 

The proper procedure is to have the car off the ground and level. Four jackstands at the jacking support points would be best for those without a lift.

If you put the fill plug back when the transmission is at the max. temp. there will be less fluid than at the min. I attempt to start the plug at 30 deg C.

 

Sounds like the right thing, I just cranked it with all brakes on, and there was no hint of a forward or reverse... Any ideas appreciated. I'm trying to get all the info and insight before I involve a professiona, I wish motorcarman was nearby. Will P

 

Also good to know. Please keep up with me, I appreciate the input. I'm gonna have to enlist my friend to help reposition it. Thank so much, Will

 

I meant no hint of reverse or neutral and wants to go in drive......

 

I am not a transmission guy, so i am going out on a limb: I think you need to order the new valve body and then take the transmission down and redo it. Something inside is not right (bolt not torqued, shaft not seated sufficiently, etc). Low or wrong fluid wouldn't cause the creeping problem in park. I would concentrate on those items that change when the shifter position changes.

 

You might be right and I working down the list of possibilities. I'm going to start with the fluid levels and then maybe new codes at transmission shop. You are right it is really an odd and unnerving a bit to me. Thanks for the input and I will update this as I go along and may very well have to effect all the things you mentioned. That sounds sound me. Will P

 

Would it damage my transmission if I pulled it backward with a chain from a pickup truck. It is stuck in drive in all positions, and turns only forward except in park in which it stops both ways and having tried to push it backward out of the driveway with two bodies, it moves a few inches then stop. My problem is that the jag is in my driveway by my house on packed gravel (and my efforts to day that were precarious and my only exit is backward. I don't want to cause futher damaging something. If I cant do that I guess it would take a tow setup that could pull the rear end off the ground


I had decided not to try to top up the fluid because of the danger of where I have it, the way it pulls forward against itself , the surface of the ground and my beat up ole body. I'm still deciding on my next move.....

Any Ideas........ Will

 

You need to rent an auto dolly -- if you can find one. Jack up the back, slip the dolly under, move where you want. Barring that, the tow truck.

 

Thanks Jim, I hadn't thought of a dolly, duh. That or the tow truck. Will

 

Well I found a couple of dolly's at harbour freight, and i'll get 4 sheets (will have to shuffle them constantly) of the pressed wood 4'x8' to enable rolling. If I get it back far enough I can drive it forward in a loop, back to the street and I can put it there til I find a decent mechanic or make a decision.. Will P

 

This sounds very like the problem I had when I rebuilt my gearbox a few years ago. In my case it was simply that the selector rod had not been engaged properly internally (the assembly instructions I was using didn't mention that!).

The mechanical notches that you feel when selecting different gears comes from the selector. It does not mean that that the rod inside is actually moving things around.

Just drop the sump and check, it's got to be worth a look.