Greetings,

I’m looking for some advice from anyone who might guide me with a problem I’m experiencing after a trans replacement. We lost the “A” drum in my wife’s XK8 at 115k miles. I found a reputable rebuilder and installed an exchange.

The problem is when I first start out from park to drive or reverse to drive it will not shift out of first. If I start from second, and wait till it shifts to second, witch it will do, then shift to drive, it will shift through all gears appropriately. And after using this method to get it out of first, I can stop completely, and then take off, and from then on it will go up and down through all the gears in a normal fashion. Even with repeated stops and starts. No MIL’s, no faults and no codes(" P's"OBD11)

I have been studying the JTIS and the info at Gus’ site and can not seem to figure this one out. The rebuilder will exchange w/out any questions asked but that involves a bit of labor. So I thought before I go through that I would ask if there might be something else, like swaping out the valve body. Once it is shifting correctly it runs good and tight, might it be a problem with the rotary switch?, there is no indication that there is any special alignment procedures, You just slide it over the spline and bolt it down, correct? Anyway's I very much wait in anticipation for some very much appreciated knowledge and advice.

Thanks

 

Initial thought is of the fliud level being incorrect, sticking solenoid or valve. You could try clearing the adaptations first, the tranny shop should have the software to do it, or else its dealer visit time.

 

Is there a warranty on the work? It seems a reputable rebuilder would warrant the job for at least a few days. if I paid someone to fix my tranny, I would expect it to work for awhile.

 

oldmots
There is definitely a warranty.(I may sound like a fool) But if it sounds like a solenoid issue, dropping out the valve body is a lot less labor than the whole unit.
Thanks

 

It is very possible that the rotary switch is either out of adjustment or faulty. Check the wiring harnesses and connectors on the tranny while you're at it.

 

How about usung a scan tool to verify thet the computer is reading the proper range that you select? Like the range selector "may be seeing only 1st gear when you select drive? Not likely, but who knows? That would at least answer the rotary switch (PRNDL) question. My guess is that you will be swapping out a solenoid or two before it's over. Again, monitor that stuff on a good scanner. (I have a Launch that works pretty well on European cars.)

 

Chopr
I think I have ruled out the rotary switch, it's my original, and the car will not start in a go gear (R or D). I think I have narrowed it down to the out put speed sensor. I'm getting a P0735 code, gear control malfunction-5th. JTIS is indicating it is ether the input or output sensor. And the input sensor will give an OBD11 when faulty, and it is not showing. So sat. I'll get this kitty backup into the air and swap it out, we'll see happens and I'll report back . oh yea is "Launch" the manufacture of your scanner?

 

Cutecat, do a search for threads authored by me, with p0735 as keyword. Newer tranjy, same code though.

 

The Launch scanner is made by Diagun. I have one that is several years old now. Kind of a Palm Pilot style unit. Uses a stylus, etc. It works amazingly well on most exclusive european cars, as well as the mainstream cars and trucks. We have trouble in our shop with trying to perform certain "manufacturer proprietary" functions, and the Launch will handle the popular things. I imagine the newer version to be just that much better. Never found any scan tool to do them ALL! I just bought a C'reader by Launch to have for a handy backup scanner. It shows live data, etc for $100 online. Matco now sells a Launch C'resetter that does even more than my C'reader. About $140 for that one. So there you have it!

 

It's Sat. evening and as I indicated I got her back up into the air today and replaced the output sensor and wa-la she's back on the road. shifting is good and responsive, much crisper than before we lost the A drum. Oh yea on the rotary switch I double checked its mounting and as I remembered it will only go on one way. I want to just briefly explain how clever, I found out, this car is. All electronic controlled shifting that works by determining input speed(from engine) and output speed( at drive shaft) to determine the correct gear. So when the output sensor failed, witch kept it from shifting out of 1st when in drive, it reverted to the speed sensors at the rear wheels(traction control/ABS) to help with gear selection. Very sophisticated.
Anyways thanks to all for your help, until next time.

 

Thanks I'll take a look at them

 

Any details or writeup on how to change the output sensor? To my knowledge, there hasn't been a DIY procedure posted previously on the forum. You'd be a pioneer if you did one.

 

Sure, Not a problem

I think the two major obstacles to conceder for the DIY’er is getting the car up in the air high enough to be comfortable to work and having away to pump the fluid back into the transmission. Other than that, it’s pretty much just wrench turning. Also downloading the JTIS manual (do a search on this forum)is a must. The instructions in the manual are straight forward, giving step by step and torque specs.

In addition to the replacement sensor, you’ll need a new pan gasket, leeks are not allowed. So once the car is safely up in the air and level, start by draining the fluid, because the trany was a fresh rebuild and there was no hardware damage, I saved every drop. I used a brand new oil drain pan, keeping that juice as clean as possible. I might conceder a fluid change if your fluid has over 60k or so, they say the fluid is life time 100k, your call, keep in mind the type you use, I used Pentosen ATF1. Next I removed the pan. A little trick I picked up from the transmission shop when the car was originally diagnosed, using a no.30 torques socket on an extension, tap it into the head of the pan screw to seat it before putting a wrench to them. I found out the hard way, these screws are softerthan you’d expect. Once the pan is off, the input and output sensors are easy to locate, they are centered at the front and back just inside the pan, secured by a retaining clip and a screw.

Now comes the fun part, after it’s all put back together, how to get a gallon+ of fluid back into the trany, there’s no just poring it in. So this is what I came up with, I started out with a 4cc syringe with a foot of polyvinyl hose that I had from a previous project. I'm sorry but I personally do not have that kind of patients.Then I remembered an empty one gallon dish washing detergent bottle that has a pump dispenser in the recycling bin, a thorough cleaning, drying and a bit of larger hose and now I’m back in business! Using the syringe to get the last couple of oz.back in. Carefully follow the instructions in the JTIS and you should not have any issues. Well there you have it, I hope I was able to convey what I found to be a fairly easy and straight forward job. The hard part was the diagnosis.

Again thanks to all and until next time,