Nodge68
Well-Known Member
This is accurate, but there also needs to be some common sense applied, as no fluid will last 150k, actually 75k is too long, 50k fluid changes is much more sensible, if expensive trouble is to be avoided.
Make sure you change the Haldex fluid and filter, rear diff oil and PTU oil too, as those are all liable to fail, if fluids are left until the LR internal.
andyfreelandy
Well-Known Member
Interesting thread. While we are 'torquing converters' (see what I did there!!) my aged TD4 FL1, 175k on original auto box, with regular 50k fluid changes is vibrating when accelerating on hills or towing.
Improved and not noticeable on the flat since I changed a drive shaft.
It does appear to be like the above, when TC is not locked. Is there a simple TC test? What actually wears out seeing as the TC is two discs and some fluid!! Probably over simplified that!!
Is it worth putting Dr wotsits stuff in??
Thanks
Improved and not noticeable on the flat since I changed a drive shaft.
It does appear to be like the above, when TC is not locked. Is there a simple TC test? What actually wears out seeing as the TC is two discs and some fluid!! Probably over simplified that!!
Is it worth putting Dr wotsits stuff in??
Thanks
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Nodge68
Well-Known Member
Clever.
What happens over time, is the lock-up clutch inside the TC wears out, and begins to skip when it engages (similar to manual box clutch judder). The TC clutch is there to minimise TC slip when it's not helpful, like when cruising or remaining as one speed for a period of time.
This TC lock-up clutch wear issue is only really evident on modern TCM controlled boxes, where the TCM modulates the fluid supply to the TC clutch servo. Older mechanical valve block control auto boxes didn't suffer much TC clutch wear, partly because the clutch was used much less frequently, but also because the clutch engagement was almost instant, without any modulated slip.
While modern modulated slip gives smooth clutch engagement, much like slipping the clutch between changes on a manual box, it does have side effects. An auto box is full of fluid which, which over time begins to become contaminated with abrasive particles, removed from all the clutch plates during normal operation.
If the old contaminated fluid is allowed to remain in the gearbox, then over time the fluid effectively turns into a grinding liquid, which strip off more plate material, contaminating the fluid further, so the cycle continues.
TC clutch shudder is often the first sign of impending friction surface wear, as the TC clutch is under the most load.
Apart from the TC lock-up clutch, the TC is virtually indestructible under normal use, as it has nothing inside other than vanes to direct the fluid around the assembly.
There are occasions when the vanes can be damaged, like running low on fluid, which can draw air around the system. This air will cause cavitation bubbles and local surface stripping of the vanes in the TC, which if l allowed to continue, will render the whole TC as scrap.
Incidentally, the TC clutch can be replaced, although it needs to be done by a specialist, with suitable cutting, welding and balancing equipment.
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andyfreelandy
Well-Known Member
Thanks, helpful description so the TC lock up clutch is part of the TC and would be replaced if the TC was changed?
So this also fits with my on hills and under load vibration issue.
I have ordered some Dr Trans shudder stuff. If it helps it sort of confirms the problem I think?
So this also fits with my on hills and under load vibration issue.
I have ordered some Dr Trans shudder stuff. If it helps it sort of confirms the problem I think?
andyfreelandy
Well-Known Member
Incidentally, why do all manuals suggest the world will end if you remove the TC??
How do you ever replace it!!
How do you ever replace it!!
Nodge68
Well-Known Member
Yes that's correct. Replacing the TC would give you a nice new TC clutch, as it's inside the TC housing.
In my experience, Dr Trany Shudder fix, does exactly what it says on the tube.
I don't know, as replacing the TC is no different to replacing the clutch in a manual box. It's a large donut shaped fluid clutch assembly, which simply sits between the gearbox and engine drive plate.Incidentally, why do all manuals suggest the world will end if you remove the TC??
How do you ever replace it!!
Once the box is out, the TC simply slips off the input shaft, and a replacement is simply slipped back in to the box.
Getting the box out is 99% of the work, changing the TC is just 1%.
Mud Plugger 6 9
Member
The Haldex is done, I'll put the rear diff oil and PTU on the shopping list..... That can happen sooner now the gearbox isn't being dropped out!This is accurate, but there also needs to be some common sense applied, as no fluid will last 150k, actually 75k is too long, 50k fluid changes is much more sensible, if expensive trouble is to be avoided.
Make sure you change the Haldex fluid and filter, rear diff oil and PTU oil too, as those are all liable to fail, if fluids are left until the LR internal.
andyfreelandy
Well-Known Member
Put Dr Trannys anti vibration juice in today.
Massive improvement. So what does it mean and how does it work?
The adverts suggest it is not a long term fix but can it be reapplied say every year or so?
Mistified as to how it stops a worn clutch vibrating, but it does indeed appear to do that. Thanks for the tip, means I can out off changing the TC for now at least.
Massive improvement. So what does it mean and how does it work?
The adverts suggest it is not a long term fix but can it be reapplied say every year or so?
Mistified as to how it stops a worn clutch vibrating, but it does indeed appear to do that. Thanks for the tip, means I can out off changing the TC for now at least.
Nodge68
Well-Known Member
Dr Tranny's shudder fix is a fiction modifier. What it effectively does is allows the clutch plates to slip over each other slightly, rather than grab, which is what causes the shudder. It's not a permanent fix as the clutches will still wear, as they now slip, however they don't remove so much friction material while slipping into engagement, so it can extend the life of the transmission by quite a bit.
I'd use it as a way of preventing more transmission damage, while saving up or deciding if the transmission is worthwhile rebuilding.
andyfreelandy
Well-Known Member
Yes, thanks. Will set me contact at the local breakers into finding me a low mileage jatco and TC when one comes in.
Some hope, but worth an ask.
Some hope, but worth an ask.
Nodge68
Well-Known Member
Dr Tranny Shudder Fix does work to stop the shudder. However it's a fraction modifier, so reduces fraction on the brake bands and clutch pack, causing those to wear faster.
So it gives with one hand, and takes with the other.
Nodge68
Well-Known Member
You need to be 100% sure the TC is causing the fault before committing to having it replaced.
You'll get little or no change out of £1,000.
After having added the Dr Tranny fluid and it worked then went bad again a couple months later I am optimistic that it is the TC.Had the fluid changed prior to adding the fix and that made no difference ,only went good when added fix.
What else could it be ?
Nodge68
Well-Known Member
Be aware that Dr Tranny works by making the clutch in the TC more slippery. Unfortunately a byproduct of this is it makes all the transmission clutches more likely to slip.
So you need to make sure that the transmission is thoroughly flushed out before the new TC goes in, or accelerated clutch wear will take place over time.
You need to make sure that it's definitely not an engine borne vibration from a failing injector or crank sensor, as these can also cause issues that feel like the TC to an inexperienced technician.
