V8 - Is it worth proactively overhauling gearbox before it blows up ?

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Thanks Saint for the very helpful input - so, if the TC was replaced due to the bearing failure and the knock on affects you mention, would there be any symptoms apparent if the underlying failing bearing was not replaced at the same time?

I will try and get some additional info regarding why he changed the TC and if he has more info re exactly what other work was done, I know it was done very recently and (he says) the gearbox work perfectly now.

Re the worst case scenario you describe involving replaceing all the friction plates in the box....plus TC, O ring and bearing.... any idea on likely cost assuming I remove and replace the gearbox myself, given that the TC itself should not need replacing...??

Cheers,

Jerry
ps 5 speed manual box in my current P38 seems like a very good option right now ;-)
 
Saint.V8 said:
When the A clutch starts to slip, the Lock Up Clutch in the TC starts to work harder as the system is designed to limit TC slippage to around 3%....with the A clutch (which is used in all gears bar 5th and I think Reverse) slipping, the LUC has to work over time prematurly wearing out the LUC friction material leading to debris in the Oil and filter...this then gets into the box and acts like a fine cutting paste wearing out the gearbox clutch packs friction plates....
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There's no need to worry about any of the six clutch packs in the 5HP24 slipping once a gear is engaged. The moment the speed sensors indicate a speed mismatch in any gear the ECU immediately puts the transmission into failsafe mode to protect the clutches. The control system is extremely sensitive to this, which can be frustrating at times.
 
jerrytlr said:
Thanks Saint for the very helpful input - so, if the TC was replaced due to the bearing failure and the knock on affects you mention, would there be any symptoms apparent if the underlying failing bearing was not replaced at the same time?

I will try and get some additional info regarding why he changed the TC and if he has more info re exactly what other work was done, I know it was done very recently and (he says) the gearbox work perfectly now.

Re the worst case scenario you describe involving replaceing all the friction plates in the box....plus TC, O ring and bearing.... any idea on likely cost assuming I remove and replace the gearbox myself, given that the TC itself should not need replacing...??

Cheers,

Jerry
ps 5 speed manual box in my current P38 seems like a very good option right now ;-)
Click to expand...
The man to ask is a member on here called Bemble (RRPhil on other forums) he is a ZF genius, when I first noticed odd vibrations from my box, I searched his posts and read them for days - he knows his mustard...and All i do is try and relay his wisdom in the best way I can.

It can be done yourself if you are handy with the spanners and are willing to take it on - I have seen the parts quoted at a full reseal kit plus friction plates for around the £600 mark (again Bemble/RRPhil will give you a better guide)....

Search for RRPhil's posts on www.rangerovers.net as he frequents there more than here....and he details the full teardown and rebuild on there....

He does the rebuild himself part time as a hobby....if you can get the box off and ship it to him, he will work on it and deliver back to you rebuilt for the price of the rebuild kit and no doubt a few beer tokens...but he does do it part time, and could be off the car for a fe wdays or more....and you'll have to get it off and on the car again....but trust me, he knows this box better than most!!
 
Bemble said:
There's no need to worry about any of the six clutch packs in the 5HP24 slipping once a gear is engaged. The moment the speed sensors indicate a speed mismatch in any gear the ECU immediately puts the transmission into failsafe mode to protect the clutches. The control system is extremely sensitive to this, which can be frustrating at times.
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Noted Bemble....I will revise my future advise to others to note this....

I do hope you don't mind be passing on what I have learned from you to others, I do note when I post, that the credit goes to you for what I impart....
 
Saint.V8 said:
The fail point on the GM box is the Valve Block - particularly with the pressure modulation solenoid to the Torque Converter Lock Up Clutch wears out the bore which reduces the pressure to the LUC which causes premature wear.

This wear dumps friction material into the oils which then acts like a cutting paste causing addtional wear....

Cleaning and filter change will only delay the inevitable.

The problem is the Valve Block which can be replaced with one from the company whos name I can never remember called Solex, Sonnex or Sonax or something like that!
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If I was today to make an offer on a 2 owner facelift 55 plate TD6 with 80k miles..

What preventative work should I ask the selling garage to do on the auto box and other bits too (gearbox has not been replaced or reconditioned to date)?...

And whilst only a 2 owner car, what are the tell tale signs if someone has been ragging and overstressing a TD6 wishing it was supercharged???
 
pld118 said:
If I was today to make an offer on a 2 owner facelift 55 plate TD6 with 80k miles..

What preventative work should I ask the selling garage to do on the auto box and other bits too (gearbox has not been replaced or reconditioned to date)?...

And whilst only a 2 owner car, what are the tell tale signs if someone has been ragging and overstressing a TD6 wishing it was supercharged???
Click to expand...

Especially on the td6 models the gearboxes are weak

The typical rate of gearboxes on the td6's usually give in at the 90k mark.

Best to get the gearbox filter changed and oil changed

The condition Of the oil will determine the condition of the gearbox.

80k mikes isn't far off

Depending on its previous life on how it was driven

Some are known to have last well over 130k on the original gearbox !
 
+1 to Hippo...

Get the oil drained and filter changed - ask them to show you the fluid and filter, if it has a metallic sheen to it or any signs of debris and such like...with a burnt smell it may be on its way south...

The trouble with the original TD6/GM box is not if it goes but when....

Fitting a the new revised Valve Block and a remanufactured Torque Convertor is reportedly the only peace of mind for the GM box....yes a rebuild will last you another 100k miles.....which is probably more than you will need it for....just depends if your gonna keep the car for life or trade in for a newer model 3 years down the line...!!
 
Bemble said:
It’s common for the torque converter lock-up clutch in the ZF 5HP24 transmission to wear just sufficiently to cause it produce the characteristic ‘cattle grid’ noise/vibration during the engagement & disengagement of its continuous slip mode – usually once the vehicle mileage gets to around the 100k mark. The fluid is not unduly contaminated as there’s still sufficient friction material left on the plate to prevent metal-to-metal contact. A replacement torque converter fixes the vibration issue and hopefully the fluid would have been replaced at the same time too. I had mine done around 20k miles ago and all is still well. The photo below shows the LUC friction plate from my old converter.

(deleted)
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Hi Bemble first of all thank you very much for taking the trouble to reply to my posts, your info is really helpful.

I have obtained a bit more info from the seller - he says he took it to Autobox because of a slight rumble at 30mph... they diagnosed TC immediately and put a new one in. Does this sound like it could have been the same issue that you had with yours?

Many thanks again

Cheers,

Jerry
 
jerrytlr said:
Hi Bemble first of all thank you very much for taking the trouble to reply to my posts, your info is really helpful.

I have obtained a bit more info from the seller - he says he took it to Autobox because of a slight rumble at 30mph... they diagnosed TC immediately and put a new one in. Does this sound like it could have been the same issue that you had with yours?

Many thanks again

Cheers,

Jerry
Click to expand...

Just make sure you have proof if this with a receipt
 
Saint.V8 said:
+1 to Hippo...

Get the oil drained and filter changed - ask them to show you the fluid and filter, if it has a metallic sheen to it or any signs of debris and such like...with a burnt smell it may be on its way south...

The trouble with the original TD6/GM box is not if it goes but when....

Fitting a the new revised Valve Block and a remanufactured Torque Convertor is reportedly the only peace of mind for the GM box....yes a rebuild will last you another 100k miles.....which is probably more than you will need it for....just depends if your gonna keep the car for life or trade in for a newer model 3 years down the line...!!
Click to expand...

How much does buying and fitting (how many hours labour) a revised Valve Block and remanufact TC cost please?
 
pld118 said:
How much does buying and fitting (how many hours labour) a revised Valve Block and remanufact TC cost please?
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Not sure on Valve Block cost - not cheap me thinks

Hippo has had his box refurbed, he may be able to shed further light on such things, but I am guessing a TC would be £400 odd.

You'll need a new oil cooler too as any debris in the system clogs this up so best to replace while the work is being done.

I am thinking a box rebuild would be close to £2.5k
 
jerrytlr said:
I have obtained a bit more info from the seller - he says he took it to Autobox because of a slight rumble at 30mph... they diagnosed TC immediately and put a new one in. Does this sound like it could have been the same issue that you had with yours?
Click to expand...
Yes, that sounds like the lock-up clutch issue. 30mph at light throttle in 4th gear (i.e. in 'D') up a slight incline is usually the condition that shows it up most.
 
Saint.V8 said:
Not sure on Valve Block cost - not cheap me thinks

Hippo has had his box refurbed, he may be able to shed further light on such things, but I am guessing a TC would be £400 odd.

You'll need a new oil cooler too as any debris in the system clogs this up so best to replace while the work is being done.

I am thinking a box rebuild would be close to £2.5k
Click to expand...

Food for thought.. Do you think a gearbox fail on an 80k mls car would be covered on a warranty or would the 'wear and tear' clause kick in???
 
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pld118 said:
Food for thought.. Do you think a gearbox fail on an 80k mls car would be covered on a warranty or would the 'wear and tear' clause kick in???
Click to expand...

Just a thought, but check any warranty very carefully...especially the small print!!

There are a lot of exclusions that the warranties don't cover...and more often than not the main exclusion is the GEARBOX!!
 
Tis me who had the gearbox recon'd innit! All in for £1300.00 at Transmission Technology in Solihull for my td6. Very reasonable considering they recon'd the g-box and torque converter as well. Nice chap as well!
 
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