so I decided to start a seperate thread about my tranny issues.



So the tranny has had issues since day one. Same issues even after...

I've had the pan and valve body off shift kit installed. All cleaned new fluid filter etc. Fluid level is just below max line at temperature before you ask.

New vacumm modulator as well.

I checked the vacuum line and im getting about 17 on it which is in the green zone. I've read close to 20 is good. So is 17 good?

What works

Park Reverse and neutral all act as they should.

Yes ive adjusted the linkage. Its correct. And new as well.

Issue is that when I put it in D and hit the gas its really slow to move. And if im moving at say 20kph and gas it it just revs but no change.

2nd isn't much better but has a tiny bit more pull.

1st...well it just acts like its in neutral weather moving or sitting still.

Now before suggesting about getting up to a higher speed to force shifting etc i am unable to do that as this car is not road legal and the subdivision i live in has short streets. Im already taking a risk by just going up and down the street to maybe 40 kph. If I **** off a nieghbour ill be in big **** lol.

I'm thinking maybe checking the governor out next?

Any thoughts etc or maybe. I'm gonna keep reading and maybe ill find something.

I should say it seems a little better than yesterday and a little better than the day before that. Maybe there's some old fluid still lingering from the torque converter. But ive drained the fluid twice now and its nice and red so maybe not.

Ive been letting it run for about 30 minutes which periodically cycling all the positions and a quick drive around a short block.

Now having all said that is it a small possibility that because the engine needs some freshing up. New everything from the valve covers up. Could that cause a tranny issue?

Just spit balling ideas.

Now let me know yours.

I know I did the shift kit properly as this was the same issue as before i put it in and im confident I did it right. Was easy to do and instructions were clear plus lots of youtube videos. You can go into my build thread to see more details.

Thanks in advance. I'm off Tomorrow so ill be smashing my head about it lol

 

Take it to a Trans shop, pay the $140 (or whatever) to Diag the issue then take that paper and promptly tow it back home. There now you'll have the problem, and I'm assuming you want to do the work yourself? You can usually get away with a AAA call to do it free if your in the states, most countries have that automobile association thing with free towing etcetc.

You've thrown a few darts at it with no luck, so this minor cost may be worth it. I do the same with my ford diesel let the overly conservative ford techs figure out the issue as per Ford specs/protocols, then promptly disregard their repair estimate and do my own job at 0 labour cost + parts.

 

Thats my final option if I can't get anything more out of here.

And i did that with my wifes ford edge. And fixed the issues myself lol.

I have one or 2 more darts to through at it though lol.

 

Torque convertor on its last legs?

Trans worn out?

My gut feeling is that this isn't gonna have an inexpensive ending, sorry.

Cheers
DD

 

How many km are on it? It sound similar to mine at around 160,000 km the spring clutches inside are known to break, and in my trans that meant first and third were engaged at the same time. I'm not sure of the exact name, but it's a plates in the clutch pack that have scallops around the edge and they break there with age, with jams the clutch pack on, even if it should be free wheeling. It may be trans rebuild time.

The case is unique to Jaguar, but the internals are the same as any other GM TH400 so you can get a kit off Rockauto or whereever.

 

94k km

 

Mine has 95 miles on it and I know the previous owner installed a secondhand trans, not sure if any work was done. But he said he spent $1500 which tells me no work was done.
Fingers crossed the trans lasts for a while yet. And here I was thinking the 400 was a truck box and an over kill that would never die?
How stupid am I?

 

It was introduced in 1964 for Cadillac, and used in many of the large GM cars through the 1960's and 70's, it was a mainstay transmission for General Motors. Yes, used in trucks too. Like any mechanical device though it has a finite life, and it often seems that the clucth steels can fail around 100,000 miles. In the 1970's that was a long life for a car.

 

Well i attempted to get the governor out. No access panel fyi in my 88. After removing the tranny mount, heat shield, and another little bracket i got the cover off. About a litre of fluid came out, and then I tried turning it as per Kirbys book, didn't move. Thats a good thing i guess. So I wanted to pull it out to inspect it for wear. Well I guess jaguar decided that let's remove the acces panel and force the owner to drop the transmission in order to get it out at some point to make more money.

As far as i could gct it out before it hits the tunnel wall.

How it sits


As far as i could get it out. Fml.

 

Oh and i got some quotes. 1200 cdn to do the tranny. 1700cdn if the tranny is in the car.

So I guess you know what I'm saying lol.

 

It’s a common problem if a little $5 nylon bushing is installed wrong.

 

LOONIES! Where do you live?

 

Yup, back in the they'd often start slipping at 100k. I remember it well. Sometimes more, sometimes less. In most applications they were set up for s-o-f-t shifts...which doesn't do anything for longevity.

They're known as a strong transmission, and they are....in terms of coping with power and weight. Long life? Not so much.

Cheers
DD

 

depends on two things. How hard they are worked. And how well they are maintained.
Fluid should be changed at 60,000 miles or every 5 years. If you skip it the wear really grows. Occasional Racing or towing change goes down to 30,000 miles 2 years. Oil temps over 230 change it immediately

 

SE ontario. only one decent shop around. mostr people do their own stuff around here

 

It sounds like you are not applying the forward clutch. Are you sure the check ***** were all installed properly after removing the valve body? I doubt the governor is the issue, that would not cause it to loose drive in manual first. Even with the governor only partially removed you probably can see if the valve, that is in the middle of the hollow shaft, moves when the fly weights are moved in and out. you can see it through the slot cut into the side of the shaft. There is some good TH400 info here. https://www.ckperformance.com/Files/...CES%20A%20.pdf

 

ya i was able to see it moving. and yes i tripled checked those little *****. mine actually had 7 but you use the supplied 5 with the shift kit. if you go to my build thread and go back a few pages you will see the condition of the filter in pan when i removed it so it wouldnt surprise me if the clutches are burnt too.

 

Well i went digging again and thinking. So I pulled the vacuum modulator which is new and I know is ok. I checked the valve behind it and it is stuck/sticking and from what I have read it should be moving freely. I just did this and its dark now so I'm gonna jump at it tomorrow morning and see if I can get it free with a magnet and needle nose pliers. When I removed the valve body I never thought to or look at this valve as its in the case. So if its gummed up with old crude that would make sense. Hopefully I can wiggle it out, give it a polish and slide it back in.

Fingers crossed.

 

Tried all day and various methods i found online like razors blades, putty knife, bfh, etc except heat to get the tran pan off. Stuck on there hard with "the right stuff" from permatex.

I'm done messing with it today. I'll try again tomorrow.

 

When I bought my '89 XJS with about 100k the transmission was slipping in drive. The car would make it to 45-50 mph. but hard acceleration would cause the revs to soar so you knew that it was slipping.. I bought the car from an estate sale and knew that it had sat for several years of more. My Father in Law had an early Eighties Cadillac Fleetwood which had sat a few years before his death, back in the Nineties. The car would run but it wouldn't engage in reverse of drive. It was a bit low on fluid so I added some of the Lucas Transmission "miracle in a bottle" and the appropriate amount of fluid. I was sure to add some gas as the next process took a couple of hours. I ran the motor and and engaged all the transmission positions; low, drive, neutral, reverse, park, and back to drive. I didn't rev the motor just let it idle. After a while I felt the car pull a bit on engaging drive then pull a bit on engaging reverse. Over time I let it back the length of the drive way then drove it forward the same distance. I wasn't going to back it into the street only to have to push it back up into the driveway should the tranny fail. This went on for a time then I checked the level and added a bit more miracle juice. I took a chance and started to drive the car around the block. I would start from a stop, let it upshift then come to a complete stop again, engage reverse back up again, Then drive around again. I suppose that the tranny was gummed up a bit from sitting. The car drove fine after this and was sold at the estate sale.

So I had a lot of hope for my XJS and it's Turbo 400. This time I changed the fluid and filter first then tried this process out. Long story short, it didn't work this time. I checked some valve in the transmission that could cause this problem but it didn't help. I think that it was the forward clutch, or something that was going bad, and the tranny finally died completely, luckily the car was in my driveway.

There wasn't going to be a cheap way out, This is where you'll discover that your Tubo 400, because it's in a Jag, is made with gold innards! At least that's the impression you get from any transmission shop you ask about a rebuild. Once the name Jaguar slips out, either they think that you are a cash cow or they just don't want to work on it-period. They may quote you some ridiculous price just to make you go away. Trying to find the shop to do the rebuild will be the biggest obstacle. I'd look around for an independent shop and ask them about it. It might take a while. Visit a few, until you find someone willing to rebuild the loose transmission that you will remove and install on your own.

It's not easy to do it yourself but it can be done with floor jacks, stands and ramps. I don't know if this is poor etiquette to mention this here, but I covered this in my April 8th. 2017 entry in my blog. Check it out. I hope that you can benefit from my experience. Best of luck!