help! jatco td4 auto box

Hi, I have a 2001 td4 auto thats slipping changing from 3rd to 4th and 4th to 5th also slips under acceleration in 4th. Not bad when cold but gets a lot worse when hot. Now then, iv stripped out the box and removed the high clutch piston and reverse piston. Theres what looks like a hairline crack in the piston and the friction plates look burnt. I have never played with one of these auto boxes before so any help would be greatly appreciated. What i would like tho know is.....

1, Is the piston going to be at fault or is it just a manufacture mark?

2, does anybody know the tolerances of thr friction plates and steels as i don want to replace them if there ok?

3, where do i go to buy the parts for it?

Many thanks in advance and heres a few pics of my findings so far......

People always help out more if you introduce yourself in the proper sections first

DaddyCoolJordan said:

People always help out more if you introduce yourself in the proper sections first

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Yes iv just done that thanks

The Jatco is in many vehicles, in the Rover 75, Volkswagen and Mazda.

If you read this post The 75 and ZT Owners Club Forums - View Single Post - 99 Rover 75 2.0 v6 Club Auto - Odd gear change & puzzled.
Someone posted their replacement of the same parts due to the same fault.

This here is good reading too
Autobox problems - possible cause? - Page 2 - The 75 and ZT Owners Club Forums

jpat.co.uk has been well recommended by others in the UK.

For more ready this forum link has the mazda documents on the transmission, the electronics are not compatible, but the physical components mostly are thus great for information.

MPVClub.com :: View topic - 03 MPV transmission jerking and won't shift


http://www.atra.com/bulletins/2006/july/atb1021.pdf

I would replace the steel plate and clutch pack based on what on your pictures and what others are saying in other forums.

Google Jatco Cracked Reversed Piston if you wants more reading.. But feel free to ask specific question here. I would rather a first post like yours with pictures and details then to know the colour of your Freelander..

Forgot to add it is a manufacture fault, but as far as I know only Mazda and Jaguar ever formally acknowledged the cause.

http://www.jagrepair.com/images/TSB...941 JATCO JF506E Transmission Replacement.pdf

zefrench said:

The Jatco is in many vehicles, in the Rover 75, Volkswagen and Mazda.

If you read this post The 75 and ZT Owners Club Forums - View Single Post - 99 Rover 75 2.0 v6 Club Auto - Odd gear change & puzzled.
Someone posted their replacement of the same parts due to the same fault.

This here is good reading too
Autobox problems - possible cause? - Page 2 - The 75 and ZT Owners Club Forums

jpat.co.uk has been well recommended by others in the UK.

For more ready this forum link has the mazda documents on the transmission, the electronics are not compatible, but the physical components mostly are thus great for information.

MPVClub.com :: View topic - 03 MPV transmission jerking and won't shift


http://www.atra.com/bulletins/2006/july/atb1021.pdf

I would replace the steel plate and clutch pack based on what on your pictures and what others are saying in other forums.

Google Jatco Cracked Reversed Piston if you wants more reading.. But feel free to ask specific question here. I would rather a first post like yours with pictures and details then to know the colour of your Freelander..

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Thanks for the info, really helpfull. I have ordered a reverse piston £45 and a seal kit £15 from sussex autos they should be here tomorrow so ill bang em in and see how it goes from there. If it still slips i will order a set of steels and plates. i will get to the bottom of it one way or another cos theres now way on earth im paying the £650 people are asking for second hand boxes!

By the way its red lol

Well done my friend for being so brave to handle such a problem,wish you all the best.Wish I had the guts.

the plates in top pics are buggered friction material is burnt,should look like these
Google Image Result for http://i00.i.aliimg.com/photo/v0/263677184/U241E_automatic_transmission_clutch_disc.jpg

New reverse piston came today, banged it in and bump! problem solved runs sweet as a nut now, all gears change smoothly and no slipping. Im super happy and celebrating with a can of stella

carcar said:

Well done my friend for being so brave to handle such a problem,wish you all the best.Wish I had the guts.

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Thankyou I always like a challenge!

johnnyspencer said:

Thankyou I always like a challenge!

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Cool fancy doing mine?

johnnyspencer said:

New reverse piston came today, banged it in and bump! problem solved runs sweet as a nut now, all gears change smoothly and no slipping. Im super happy and celebrating with a can of stella

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Thanks for letting us know. Did you change the clutch pack after all?

no, I didnt order one so I thought id try it without new ones for now. Its easy enough to put new ones in if needed later but everything seems fine so far. Apart from being a bit discoloured I think there ok. I did measure them and the friction plates are only 0.2mm less than new ones, the steels are bang on 2.0mm as new! If it starts playing up Ill get some new ones but for now its running great

Interesting fred. The split in the metal in the pic below... where does it go? Is it a split through to the other side or through to the edge?

on the other side is the piston, which clamps the clutch pack, a split will mean some pressure is lost ,reducing clamping force ,allowing clutch pack to slip at times or all the time, clutch plates wont take very much slipping before they burn out

thanks

johnnyspencer said:

New reverse piston came today, banged it in and bump! problem solved runs sweet as a nut now, all gears change smoothly and no slipping. Im super happy and celebrating with a can of stella

Click to expand...

Yes well done mate...great fix

jamesmartin said:

on the other side is the piston, which clamps the clutch pack, a split will mean some pressure is lost ,reducing clamping force ,allowing clutch pack to slip at times or all the time, clutch plates wont take very much slipping before they burn out

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Thats correct, its working fine now but I think ill change the clutch packs in 4th & 5th in the very near future just as precaution. I didnt do it at the time because I wanted to keep costs down just in case I was wrong and it didnt fix the problem. every time I hear it go into 4th & 5th I cross my fingers and think to myself... should of changed the friction plates!!!

And yes its really hard to see but it goes through to the other side so a lot of the pressure on the clutch plates is lost through the crack, makes it a bit like trying to blow up a balloon with a tiny hole in it!

Looks like mine's starting to do this too. Slips in 3rd 4th and 5th not too bad when cold. If I lift of the gas the revs drop back down and the auto box grips again and carries on....I'm pretty sure the symptoms are pointing to this cracked reverse piston I've been reading about. Now my next question is what parts do I need to buy, and can I fit them all without any special tools, as I've read you need to compress some kind of spring in the reverse piston drum? Is this true?... are the guys that have done this job still on here? Any pointers on what extra I may want to change etc.... any photos, info you guys can provide will be most welcome.