jcirulis

Member
Hello!

Problem - hard switching from gears and F4 in instrument panel.

What have i done. pluged pc, car understands what gear the shifter is on.

had idea about bad solenoid valves so i did test shown in this videos 2nd part.



all mesurments to solenoids shown resistance - 0

any idea?

can ALL of them be broken?
or problem is in wireing?


where is that pin nr 17 going, meybe thats the problem, i just dont beleve that all off them died.
 
I thought the Jatco box was just on the V6, and the TD4 one is a Getrag?
Could be wrong - maybe some TD4s used it.
 
I thought the Jatco box was just on the V6, and the TD4 one is a Getrag?
Could be wrong - maybe some TD4s used it.

All autos KV6 or TD4 use the Jatco box.
The TD4 manual is a Getrag. The 1.8K and L series diesel were only available in a manual, and both used the PG1 gearbox. ;)
 
Can the box from a KV6 be fitted straight into a TD4 without any changes??
Retaining the TD4 electrikery of course!
No. The engine side of the box casing is shaped to fit whatever engine it's being fitted to. The internal gear ratios are also different, as the engines have very different speed and torque characteristics.
The electricity bit is actually the same, but that's the only things that are common between engine types.
 
Thanks John, thought the ratios may have been different but thought they may be the same case.
Shame as the V6 is a source of lower mileage boxes.
I'm doing a fluid change on my TD4 auto as the shuddering has got worse. Box has done 175k but was refurbed at 100k.
Seems reluctant to change down on hills and feels like it is labouring badly. A down shift sorts it all out.
Will also check rear engine mount.
 
Thanks John, thought the ratios may have been different but thought they may be the same case.
Shame as the V6 is a source of lower mileage boxes.

The V6 box isn't working so hard, as the TD4 box, as the V6 has less torque, so doesn't stress the box internals as much as the TD4 engine. The TD4 is approaching the maximum torque limit of the box, but the V6 is quite a lot under its maximum torque limit.
This means the V6 box should last longer, although regular fluid changes really help too.
 
So in an effort to reduce the vibration which seemed to be there almost all of the time and worse when working, I replaced the lower engine mount (some play) and renewed the jatco fluid.

Much improved. Now have a resonant vibration at 50mph in 5th. Any other gear is fine at 50. Engine rpm is around 1750 in 5th. Again, any other gear 1750 rpm is fine!!
Beginning to think I have a resonant driveshaft.
Any other ideas please??
VCU, bearings, diff, front prop all replaced recently.
 
Yes, will recheck but at 90 deg to chassis.
Weird that it is only 5th gear. Same revs in another gear or same road speed in another gear is fine!!
Wondering if it is actually a 5th gear jatco problem. Box has done 175k. Rebuilt at 100k but you never know what was changed!!
 
Yes, will recheck but at 90 deg to chassis.
Weird that it is only 5th gear. Same revs in another gear or same road speed in another gear is fine!!
Wondering if it is actually a 5th gear jatco problem. Box has done 175k. Rebuilt at 100k but you never know what was changed!!

Well I just dropped in out of interest and saw this post, and a little bell went off in the dusty recesses of my mind.
Do you have a performance chip (synergy etc) or a remap? This alters the torque curve quite dramatically and leads to a vibration in 5th gear on the auto box and a reluctance to down shift. The computer thinks there's enough power to stay in 5th when actually it needs to downshift.
I remember mine doing this, I believe I stopped it by turning the synergy box down a notch for a couple of weeks then putting it back in the higher setting.
If you have a remap, you could remove the TCM and stick it on a shelf for a week so it forgets it's settings and retrain it, or buy another off fleabag and give that a try. Dead easy to swap over.

Anyhow, hope you're all ok in here. Keep safe.
Mike
 
Thanks. It has a bhp tuning box, so a possibility!!

Will disable and try. It would fit with the problem of it only being in 5th and not rev or speed dependent in any other gear.
Will report back. Thanks again for the idea.
 
Thanks. It has a bhp tuning box, so a possibility!!

Will disable and try. It would fit with the problem of it only being in 5th and not rev or speed dependent in any other gear.
Will report back. Thanks again for the idea.
I fitted a synergy 2a box with the eco switch on mine about 2 1/2 years ago set on 3, see pic, & it made a noticeable difference over std even in eco mode & a bigger difference when not in eco. It's done about 21,000 since & I've never any vibrations like you describe, the only vibration I've had was not long after the VCU & support bearings (supplied by Bell Eng.) were replaced & the bearings gave up the ghost after 6,000 miles, that vibration was between 40 & 50 mph & could be felt if you rested your hand on the handbrake lever (it changes into 5th about 45). I'm not sure how new your support bearings are but they vary in quality. I paid under £40 for a pair of replacement hangers but I made damm sure I removed one of the rubber seals on each bearing & packed it with a good quality grease before refitting it all & I'm glad to say it's been fine for the last 26,000 miles. (Cars done about 168,000 in total) Good luck & keep us posted.
20210308_212853.jpg
 
Used the TD4 on a fair motorway run today. The handling and feel of the car is fab with all the new bits and at 60mph plus it is quiet and smooth.

At 40 to 50moh particularly when pulling or up hill the vibration is bad. A low freq drone through the whole car.

Now it did this prior to the refurb work but I hoped new bushes, vcu, bearings, shocks, springs, trailing arms, front wishbones, wheel bearings would sort it.

Any clues?? It drones at 1750 to 2k rpm and really bad at 50mph on 5th.

Worse when accelerating.

I am thinking driveshaft as they haven't been changed although no play could be felt.

Could it be the autobox? New fluid helped but not solved by any means.

Turning boost box off makes no difference to vibration.

Could it be the torque convertor?
Now done about 170k miles. Is there anything to wear out?

Next move is to put a diagnostic microphone near the 4 driveshafts and listen to each whilst it is doing it. I have a switch box and headphones.

Would appreciate any other ideas as it spoils the drive and may be causing secondary damage.

Thanks.
 
Could there be a red herring here? Is the 5th gear thing leading you down the garden path maybe? A drone makes me think bearings. What about the wheel bearings? Is it possible one of the ones you fitted is duff? The vibration makes me wonder if a drive shaft or prop is out of balance.

Just giving basic thoughts. I'm sure you're on that though Andy.
 
Thanks, the vibration is quite bad, wheel bearing makes more noise than vibration I think based on past experience but I will check them now they have bedded in, or worn out!!

I'm going for driveshafts. They are original and the vibration was there before the refurb.

Cant decide whether to just replace both fronts or to try to narrow it down with my diagnostic microphones.

If it was a rear I'd take it off!! Not so easy on the front.

I've read that some new ones are bad for vibration. Can't find a good make.
 
Used the TD4 on a fair motorway run today. The handling and feel of the car is fab with all the new bits and at 60mph plus it is quiet and smooth.

At 40 to 50moh particularly when pulling or up hill the vibration is bad. A low freq drone through the whole car.

Now it did this prior to the refurb work but I hoped new bushes, vcu, bearings, shocks, springs, trailing arms, front wishbones, wheel bearings would sort it.

Any clues?? It drones at 1750 to 2k rpm and really bad at 50mph on 5th.

Worse when accelerating.

I am thinking driveshaft as they haven't been changed although no play could be felt.

Could it be the autobox? New fluid helped but not solved by any means.

Turning boost box off makes no difference to vibration.

Could it be the torque convertor?
Now done about 170k miles. Is there anything to wear out?

Next move is to put a diagnostic microphone near the 4 driveshafts and listen to each whilst it is doing it. I have a switch box and headphones.

Would appreciate any other ideas as it spoils the drive and may be causing secondary damage.

Thanks.
It seems to be doing it on or about when it changes into top, 45-50 depending on throttle opening. If it's in top at 40 that's too low so it would be lugging the engine which normally causes droning, what's it like if you hold it in 4th? I know it will take it out of the rev band you stated but if it still does it then at least you would know it's speed related & not revs.
Have you checked the engine/gearbox mounts? Might it be worth putting a jack under the engine slacken the mounts then retighten them.
 
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