Okay, I was headed back from visiting my daughter this weekend and was starting the 120 mile trip back from down there to here.

My car would not shift into 3rd. That's the extent. I checked the transmission fluid and it was fine.

Any pointers?

 

Numerous things will appear. My suggestions are:

Vac modulator, not doing its thing, usually a lot of smoke associated with this.

Governor nylon gear gone AWOL, common.

Blocked oil filter, lack of servicing, maybe.

Very dirty valve body due to above filter.

Bands etc failed, not common on T400 but not impossible.

Others will come up with other items, but a transmission specialist is about the only real way if the above does not restore it apart from the bands etc, which you cannot check without dissmantling the transmission.

 

Check the fluid.....check the Vac modulator vac. line for Vac and that is is on.

Should that not fix it check the shifter cable and brackets, is there any chance it is sitting in 2nd and the shifter looks like its in 3?


Change the fluid and filter add 1 bottle of lucas tranny treatment. (lucas only!!) it will loosen up a stuck valve body in 20 to 30 miles.



Brian Felts

 

The fluid is good, I checked that; and I even checked to make sure it was in drive and not 2 (both by going from P to D and from 1 to D, actually).

What is the vac modulator and where can I find it? I don't know what it looks like (though I'll be hitting up google from here).

Thanks for the suggestions. I'll take 'em in turn until I find the problem.

 

http://cgi.ebay.com/ebaymotors/GM-Tu...item4aa17f1118


Have a look at this ebay auction. Just ahead of the tranny pan on the right side you will see a shiny round modulator with the vac line on it. That will be your part. Should be cheap to replace if its bad.

Brian

 

Okay, I found it, but I can't really get to it; I can't get the car high enough to crawl under there for a good look. Even if I could, I don't know how to test if it's bad.

Out of curiousity, if the vac modulator were bad, wouldn't I have issues shifting from 1st to 2nd as well?

I got a recording (of sorts -- I took it with my blackbery and it's windy today) of the car running in park, but I'm not sure how to upload it. It's not a great recording... but there's a whine to the tranny as well. If you're interested in hearing it (if that'll even help), you can email me: 777 Dot jockey at gmail dot com

 

Well, I replaced the vacuum modulator this evening, but no joy. Reverse isn't catching now, and there's quite a whine in P and N. It's sounding like the torque converter and I've resigned myself to a transmission rebuild.

In that light and given that it's a GM transmission, is there anything special I need to keep in mind when shopping for a transmission tech?

 

Any decent trans guy can rebuild it.

It is normal procedure to use a tool to turn the flywheel when removing the transmission. Don't let the trans shop turn the engine opposite of normal rotation. It might damage the chain tensioners.

If you ever plan on running your engine up to the 6000-6500 rpm range that it is easily capable of, you'll need something better than the garden variety rebuilt torque converter that most trans shops would use. The tranny shop you use probbaly has a source for furnace brazed and highly balanced torque converters. If not contact a specialist such as TCI Transmissions

Have the tranny shop install a mild shift kit whie you're at it. the slightly firmer shifts are actually easier on the transmission

That's about it.

Cheers
DD

 

Had a further thought on your issues.

How long since the trans fluid, filter, suction o/ring was changed??.

If recently. is the suction tube "correctly" fitted.

My reasons for this is that your noises sound (I know I cant hear it) like the pump is sucking air, they make a real whine/scream noise. Now this can be from too low fluid, suction o/ring failed.

If you have not serviced it in the last 12+ months, then the above still applies, PLUS, that filter may be blocked, it is a dacron filter, and the pump can suck NOTHING, hence the noise from "trying", and of course, no fluid= no pressure= no gears, mmmm. The same if were sucking air.

If it were mine, I would drop the pan, change the filter, suction o/ring, and refill to the correct level, HOT. It may not work, but it will definately be cheaper than a trans job.

Whilst apart I would look closely at that plastic/nylon suction tube itself, it can be damaged (cracked) by some previous "mechanic" fitting it incorrectly, forcing it into the hole. It must be lined up with the pump inlet carefully, it is pretty fool proof, but I have seen 2 damaged in my time (not mine).

 

I can send a not very good recording of the noise it's making; perhaps you're familiar enough to decipher it. It sounds more mechanical to me, but I can definitely give this a shot.

 

OK, I have added you to my contacts area, instead of broadcasting my email address to the whole www for obvious reasons, I think I got it right, dunno. Send away, I will liisten and reply.

Both my XJ-S and the S2 XJ6 had this noise, teh V12 was a suction o/ring missing, my stuff up, and teh XJ6 (BW65) was low fluid by 1ltr, wrong dipstick me thinks, never went any further, just ran it 1 ltr more than the mark,, sold it 8 years later, current owner doiing the same, it still works, not rocket science, its British hahaha.

Still not saying, when was the last time the trans was serviced, 5 years ago, 5 days ago ????. The TH400 likes regular fresh oil and filter, and although a VERY strong trans, those 2 items will kill one quick time.

 

"I Broke It"
If you call an older Jaguar an "IT" your going to **** her off.

 

Nice pick up AronS, I missed that on the original post.

I reckon he needs to get a bottle of the BEST Jack Daniels around, 2 straws, one for the car, one for him, and make his peace, REAL QUICK, she will be ANGRY, trust us.

Being as "IT" is an XJ-S he is in for a LONG "forgive me" path.

Enjoy

 

Haha, you guys are funny.
The transmission's been rebuilt and the car is running just fine, shifting firmly, and other than one of the brights went out, nothing else has gone wrong with it.
I suppose I could try to say that the 'it' was specifically referring to the transmission... but I've never called my cars "she" (or "he" just to cut those jokes off at the pass! ).
But the JD suggestion's a good one. I'll make peace and share some Jack...

 

Good read guys, very entertaining and educational (as I know nothing about your V12s)

to the OP, did you get a beefier torque converter and the shift kit as suggested? Just curious...

 

[quote=h20boy;218748]Good read guys, very entertaining and educational (as I know nothing about your V12s)

Not knowing anything about V12's is a waste. What an experience, would not have missed it for "all the tea in China" (as they say), kept me sane.

NOTHING, and I mean NOTHING beats a V12 "on song and driven like you stole it", my XJ-S gets this every time it goes out, note my sig, "her cat", hahaha.

When I find a V12 X300 (not easy down here) I may upgrade from my "big block" 3.2, mmmm.

 

I think I have a similar problem as the OP and wanted to get a little input before I start pouring more money into this car.

I replaced the transmission fluid and filter about a year and a half ago. Out of the blue, my transmission started making a high pitched whine a few weeks ago. The whine increases in pitch with engine speed. I added most of a bottle of Lucas (didn't want to overfill), and it seemed to help for about a day, but the whine never completely went away and has since returned full force.

Then, as of a couple of days ago reverse has gone almost completely away. I can feel it trying to grab, and it will move the car slowly but not up any sort of incline. It seems to do fine in forward gears, although it seems to have trouble shifting into 3rd on the hiway. BTW, the whine remains, forward or reverse.

So, could it be that I installed the suction tube incorrectly and it finaly let go, or am I looking at a new transmission? Thanks in advance.

 

Doesn't sound good.

I assume you've re-checked the fluid level.

Yes, could be a filter/pick-up tube thing. Not a pleasant idea but obviously you'll have to drop the pan to inspect.

The whine could be a pump problem or the early stages of torque converter failure.

I'd start bracing for an overhaul

Others will chime in, hopefully with some less expensive ideas

Cheers
DD

 

I'll start by dropping the pan this weekend to check the filter and pick-up tube. If that's not it, I may make a transmission overhaul my winter project. I've never done that before, but I find myself saying that a lot since I've owned this car.

Thanks for the input.

 

I dropped the pan today and inspected the parts. The pick-up tube is in good shape, but it only had one o-ring and it was rock hard. I guess I didn't change that when I did the filter last time.

I checked my records, and it was 2-1/2 years and 9700 miles ago when I changed the fluid and filter. I didn't find any metal chunks this time, but it seems like there's a lot of sludge in the pan for only 9700 miles. I didn't drain the converter and cooler last time, so that might account for some of it. Is this a bad sign?

My hope is that the combination of a partially plugged filter and a bad o-ring caused the pick-up tube to leak at the connection to the valve body. Tomorrow I'll get a new filter and a couple of o-rings and put it back together. Is there anything else I should be looking at or addressing while the pan is off?