P38A Automatic Gearbox Lucas Transmission Fix

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Jonathan Wright

New Member
Posts
6
Location
London
Would very much appreciate any opinions on the following:


Range Rover P38 front prop-shaft failure transfer case end. Flailing prop-shaft breaks gearbox gear selector shaft and electronic gear position sensor. Also severely dents gearbox sump pan now slowly leaking fluid from drain plug. Also damaged catalytic converter which now rattles. Passenger footwell severely dented.


Car stuck in drive. Engine turned off. No engine re-start due to gearbox in drive engine inhibited. Winched forward on to low loader tow truck. Unloaded backwards to garage. Vehicle runs backwards off the low loader under its own weight. Garage also push the vehicle backwards in to workshop.


First question: Has the gearbox been further damaged by being unloaded backwards and pushed backwards with the vehicle in drive engine off ?


Used gearbox, transfer case and torque converter purchased for parts (ie for Gearbox sump pan, gearbox gear selector shaft and electronic gear position sensor.)


Seller says gearbox and transfer case all working perfectly when removed from his own personal P38.


Plan to replace gearbox gear selector shaft whilst gearbox remains in the vehicle. Garage very reluctant. Plan also abandoned because concerned gearbox further damaged when vehicle unloaded backwards from low loader tow truck.


Garage remove old gearbox and transfer case and fit the used gearbox and transfer case. Filled gearbox with ATF. Filter cleaned but not replaced. New front prop-shaft not yet fitted.


Garage call and say the gearbox is bad. Vehicle on two post lift in forward drive or reverse rear wheel offside turns but on the ground no forward drive or reverse and vehicle does not move. Check on gearbox fluid level shows garage have overfilled it by about 2 litres. Extra removed but makes no change. Loud whirring sound from gearbox/torque converter when in drive or reverse. Gearbox makes harsh graunching sound when put in Park.


Garage says initially the vehicle drove well on short test drive but quickly lost forward drive and reverse.


Garage swap electronic gear position sensor for used unit. No improvement. Garage check electronic connections. None are loose.


Garage say gearbox is bad. Seller contacted and confirms gearbox fully functional when removed from vehicle about 8 months ago. Garage will not work on vehicle further. No substantial grounds to suggest faulty work by them so bill paid. Driven ¼ mile home; limited forward drive possible at not less than 3000 rpm. Loud whirring sound from gearbox/torque converter.


Home Tests: front propshaft not attached; vehicle on axl stands

1.Wheels off the ground the rear offside wheel turns in forward drive and reverse.

2.Graunching sound when Park engaged.

3.In neutral rear offside wheel continue to turn but can be stopped with hand pressure.

4.Vehicle when on the ground vehicle has some limited reverse.

5.Vehicle when on the ground has no forward drive at not less than 3000rpm.


Gearbox flushed 3 times with fresh ATF. On each flush the ATF fluid is cloudy and sedimented. Gearbox magnet originally covered in grey sludge. Filter changed for quality aftermarket filter.


Further Home tests: front propshaft not attached; vehicle on the ground:

1.From cold start if vehicle put immediately in forward drive or reverse has forward drive and reverse but within 15 seconds forward drive is lost;

2.Vehicle reverses at idle;

3.No forward drive at idle;

4.Some limited forward drive possible if revs raised to 3000. Vehicle snatches forward.

5.Torque converter noisy.

6.Graunching sound when put in Park but at a reduced volume;

7.Engine off vehicle in Park noticed parking lock is inoperative. Vehicle can be pushed or runs back on slight incline unless handbrake engaged. Think parking pawl must be damaged.


Mechatronic swapped for known good mechatronic from own damaged box. ATF changed again.


Further tests: no appreciable change save perhaps reverse is minimally stronger: Drive still only achieved if revs raised to 3000.


Transmission jack purchased concluding gearbox to come out again suspecting bad torque converter or bad gearbox fluid pump. Planning to swap known good units from own damaged box. Lucas Transmission Fix added to see if any further improvement to assist with fault diagnosis.


Vehicle on axl stands front propshaft not fitted Lucas Transmission Fix added. Geabox run for 25 minutes in reverse and drive. Rear offside wheel turns. In that 25 minutes the following is observed:

1.Whirring noise from torque converter/gearbox desists.

2.Graunching when putting the gearbox in park desists.

3.In drive with engine idling the rear offside wheel noticed to now run at approximately 3 times the speed by comparison to previously.


Front prop-shaft re-fittted. Vehicle taken down from axl stands. Drive and Reverse restored. Test drive: gear box is quiet and moves smoothly through all gears. Kick down functions. Gear box Park now functions. No graunching sound when Park is engaged.


Second Question: for what reasons was full functionality returned ?


With thanks to all.
 
Would very much appreciate any opinions on the following:


Range Rover P38 front prop-shaft failure transfer case end. Flailing prop-shaft breaks gearbox gear selector shaft and electronic gear position sensor. Also severely dents gearbox sump pan now slowly leaking fluid from drain plug. Also damaged catalytic converter which now rattles. Passenger footwell severely dented.


Car stuck in drive. Engine turned off. No engine re-start due to gearbox in drive engine inhibited. Winched forward on to low loader tow truck. Unloaded backwards to garage. Vehicle runs backwards off the low loader under its own weight. Garage also push the vehicle backwards in to workshop.


First question: Has the gearbox been further damaged by being unloaded backwards and pushed backwards with the vehicle in drive engine off ?


Used gearbox, transfer case and torque converter purchased for parts (ie for Gearbox sump pan, gearbox gear selector shaft and electronic gear position sensor.)


Seller says gearbox and transfer case all working perfectly when removed from his own personal P38.


Plan to replace gearbox gear selector shaft whilst gearbox remains in the vehicle. Garage very reluctant. Plan also abandoned because concerned gearbox further damaged when vehicle unloaded backwards from low loader tow truck.


Garage remove old gearbox and transfer case and fit the used gearbox and transfer case. Filled gearbox with ATF. Filter cleaned but not replaced. New front prop-shaft not yet fitted.


Garage call and say the gearbox is bad. Vehicle on two post lift in forward drive or reverse rear wheel offside turns but on the ground no forward drive or reverse and vehicle does not move. Check on gearbox fluid level shows garage have overfilled it by about 2 litres. Extra removed but makes no change. Loud whirring sound from gearbox/torque converter when in drive or reverse. Gearbox makes harsh graunching sound when put in Park.


Garage says initially the vehicle drove well on short test drive but quickly lost forward drive and reverse.


Garage swap electronic gear position sensor for used unit. No improvement. Garage check electronic connections. None are loose.


Garage say gearbox is bad. Seller contacted and confirms gearbox fully functional when removed from vehicle about 8 months ago. Garage will not work on vehicle further. No substantial grounds to suggest faulty work by them so bill paid. Driven ¼ mile home; limited forward drive possible at not less than 3000 rpm. Loud whirring sound from gearbox/torque converter.


Home Tests: front propshaft not attached; vehicle on axl stands

1.Wheels off the ground the rear offside wheel turns in forward drive and reverse.

2.Graunching sound when Park engaged.

3.In neutral rear offside wheel continue to turn but can be stopped with hand pressure.

4.Vehicle when on the ground vehicle has some limited reverse.

5.Vehicle when on the ground has no forward drive at not less than 3000rpm.


Gearbox flushed 3 times with fresh ATF. On each flush the ATF fluid is cloudy and sedimented. Gearbox magnet originally covered in grey sludge. Filter changed for quality aftermarket filter.


Further Home tests: front propshaft not attached; vehicle on the ground:

1.From cold start if vehicle put immediately in forward drive or reverse has forward drive and reverse but within 15 seconds forward drive is lost;

2.Vehicle reverses at idle;

3.No forward drive at idle;

4.Some limited forward drive possible if revs raised to 3000. Vehicle snatches forward.

5.Torque converter noisy.

6.Graunching sound when put in Park but at a reduced volume;

7.Engine off vehicle in Park noticed parking lock is inoperative. Vehicle can be pushed or runs back on slight incline unless handbrake engaged. Think parking pawl must be damaged.


Mechatronic swapped for known good mechatronic from own damaged box. ATF changed again.


Further tests: no appreciable change save perhaps reverse is minimally stronger: Drive still only achieved if revs raised to 3000.


Transmission jack purchased concluding gearbox to come out again suspecting bad torque converter or bad gearbox fluid pump. Planning to swap known good units from own damaged box. Lucas Transmission Fix added to see if any further improvement to assist with fault diagnosis.


Vehicle on axl stands front propshaft not fitted Lucas Transmission Fix added. Geabox run for 25 minutes in reverse and drive. Rear offside wheel turns. In that 25 minutes the following is observed:

1.Whirring noise from torque converter/gearbox desists.

2.Graunching when putting the gearbox in park desists.

3.In drive with engine idling the rear offside wheel noticed to now run at approximately 3 times the speed by comparison to previously.


Front prop-shaft re-fittted. Vehicle taken down from axl stands. Drive and Reverse restored. Test drive: gear box is quiet and moves smoothly through all gears. Kick down functions. Gear box Park now functions. No graunching sound when Park is engaged.


Second Question: for what reasons was full functionality returned ?


With thanks to all.
rolling the truck off the loader wouldnt have effected box at all, not having both props on was your problem
 
Why did the garage not fit the front prop in the first place? Just hope through all this the VC hasn't taken any damage.
 
Range Rover P38 front prop-shaft failure transfer case end. Flailing prop-shaft breaks gearbox gear selector shaft and electronic gear position sensor. Also severely dents gearbox sump pan now slowly leaking fluid from drain plug. Also damaged catalytic converter which now rattles. Passenger footwell severely dented.


Car stuck in drive. Engine turned off. No engine re-start due to gearbox in drive engine inhibited. Winched forward on to low loader tow truck. Unloaded backwards to garage. Vehicle runs backwards off the low loader under its own weight. Garage also push the vehicle backwards in to workshop.


First question: Has the gearbox been further damaged by being unloaded backwards and pushed backwards with the vehicle in drive engine off ?

What! your whole drive train is fubar now...why did the prop-shaft fail? and break the gearbox selector shaft?...never mind pushing a fubar P38 off a low loader...
 
When put on and off loader ,They should have put a fuse in position 11 under drivers seat ,,transfer box,,,,,,:p...in neutral for moving, if its still there it should not drive ,but it might if things are not set up right,....The viscous unit needs to lock up to get drive with no front shaft ,if your old vc,was seized that could snap a shaft union ...:eek::eek: another wee point engine has to be running ,when checking gbox oil ,if the engine is stopped and you pull the plug you will lose about 2 ltrs and the gbox will be shy of oil ,,,ie limited drive,thats if its a newer box with no fill pipe ;)
 
Last edited:
When put on and off loader ,They should have put a fuse in position 11 under drivers seat ,,Gearbox in neutral for moving, if its still there it should not drive ,but it might if things are not set up right,....The viscous unit needs to lock up to get drive with no front shaft ,if your old vc,was seized that could snap a shaft union ...:eek::eek: another wee point engine has to be running ,when checking gbox oil ,if the engine is stopped and you pull the plug you will lose about 2 ltrs and the gbox will be shy of oil ,,,ie limited drive,thats if its a newer box with no fill pipe ;)
Just to clarify, putting a fuse in position 11 will put the transfer box in neutral not the gearbox.;)
 
Would very much appreciate any opinions on the following:


Range Rover P38 front prop-shaft failure transfer case end. Flailing prop-shaft breaks gearbox gear selector shaft and electronic gear position sensor. Also severely dents gearbox sump pan now slowly leaking fluid from drain plug. Also damaged catalytic converter which now rattles. Passenger footwell severely dented.


Car stuck in drive. Engine turned off. No engine re-start due to gearbox in drive engine inhibited. Winched forward on to low loader tow truck. Unloaded backwards to garage. Vehicle runs backwards off the low loader under its own weight. Garage also push the vehicle backwards in to workshop.


First question: Has the gearbox been further damaged by being unloaded backwards and pushed backwards with the vehicle in drive engine off ?


Used gearbox, transfer case and torque converter purchased for parts (ie for Gearbox sump pan, gearbox gear selector shaft and electronic gear position sensor.)


Seller says gearbox and transfer case all working perfectly when removed from his own personal P38.


Plan to replace gearbox gear selector shaft whilst gearbox remains in the vehicle. Garage very reluctant. Plan also abandoned because concerned gearbox further damaged when vehicle unloaded backwards from low loader tow truck.


Garage remove old gearbox and transfer case and fit the used gearbox and transfer case. Filled gearbox with ATF. Filter cleaned but not replaced. New front prop-shaft not yet fitted.


Garage call and say the gearbox is bad. Vehicle on two post lift in forward drive or reverse rear wheel offside turns but on the ground no forward drive or reverse and vehicle does not move. Check on gearbox fluid level shows garage have overfilled it by about 2 litres. Extra removed but makes no change. Loud whirring sound from gearbox/torque converter when in drive or reverse. Gearbox makes harsh graunching sound when put in Park.


Garage says initially the vehicle drove well on short test drive but quickly lost forward drive and reverse.


Garage swap electronic gear position sensor for used unit. No improvement. Garage check electronic connections. None are loose.


Garage say gearbox is bad. Seller contacted and confirms gearbox fully functional when removed from vehicle about 8 months ago. Garage will not work on vehicle further. No substantial grounds to suggest faulty work by them so bill paid. Driven ¼ mile home; limited forward drive possible at not less than 3000 rpm. Loud whirring sound from gearbox/torque converter.


Home Tests: front propshaft not attached; vehicle on axl stands

1.Wheels off the ground the rear offside wheel turns in forward drive and reverse.

2.Graunching sound when Park engaged.

3.In neutral rear offside wheel continue to turn but can be stopped with hand pressure.

4.Vehicle when on the ground vehicle has some limited reverse.

5.Vehicle when on the ground has no forward drive at not less than 3000rpm.


Gearbox flushed 3 times with fresh ATF. On each flush the ATF fluid is cloudy and sedimented. Gearbox magnet originally covered in grey sludge. Filter changed for quality aftermarket filter.


Further Home tests: front propshaft not attached; vehicle on the ground:

1.From cold start if vehicle put immediately in forward drive or reverse has forward drive and reverse but within 15 seconds forward drive is lost;

2.Vehicle reverses at idle;

3.No forward drive at idle;

4.Some limited forward drive possible if revs raised to 3000. Vehicle snatches forward.

5.Torque converter noisy.

6.Graunching sound when put in Park but at a reduced volume;

7.Engine off vehicle in Park noticed parking lock is inoperative. Vehicle can be pushed or runs back on slight incline unless handbrake engaged. Think parking pawl must be damaged.


Mechatronic swapped for known good mechatronic from own damaged box. ATF changed again.


Further tests: no appreciable change save perhaps reverse is minimally stronger: Drive still only achieved if revs raised to 3000.


Transmission jack purchased concluding gearbox to come out again suspecting bad torque converter or bad gearbox fluid pump. Planning to swap known good units from own damaged box. Lucas Transmission Fix added to see if any further improvement to assist with fault diagnosis.


Vehicle on axl stands front propshaft not fitted Lucas Transmission Fix added. Geabox run for 25 minutes in reverse and drive. Rear offside wheel turns. In that 25 minutes the following is observed:

1.Whirring noise from torque converter/gearbox desists.

2.Graunching when putting the gearbox in park desists.

3.In drive with engine idling the rear offside wheel noticed to now run at approximately 3 times the speed by comparison to previously.


Front prop-shaft re-fittted. Vehicle taken down from axl stands. Drive and Reverse restored. Test drive: gear box is quiet and moves smoothly through all gears. Kick down functions. Gear box Park now functions. No graunching sound when Park is engaged.


Second Question: for what reasons was full functionality returned ?


With thanks to all.
When the viscous coupling seized on mine it broke the uj on the shaft. At least that's what I blamed. Also dented the sump but that's all. I have used Lucas in several auto boxes to good effect but not with such startling results.
 
f the gearbox is deaded and a replacement purchased, why not do a full swap? am i missing something?
Think he did have the box changed ,the first one was beaten up when the shaft broke, he changed it and the second box is fibered ,But he was told it was good when purchased,,,,,,,,,,,Thats my understanding so far :oops: :D:D
 
Think he did have the box changed ,the first one was beaten up when the shaft broke, he changed it and the second box is fibered ,But he was told it was good when purchased,,,,,,,,,,,Thats my understanding so far :oops: :D:D
Thank you all.

I wanted to work out if the original box now out of the car just needs a new gear selector input shaft and sump. Seems the answer is yes. No damage from being backed of the low loader in drive with engine off.

What I really wanted to get to the bottom of is by what processes the Lucas Transmission Fix solved the problems of the replacement box. I just tried it with no expectation that it would work. I was frankly amazed when it did. I don't think its because the front prop shaft was yet to go on. That was only left off because it was late arriving from supplier to garage.
 
Thank you all.

I wanted to work out if the original box now out of the car just needs a new gear selector input shaft and sump. Seems the answer is yes. No damage from being backed of the low loader in drive with engine off.

What I really wanted to get to the bottom of is by what processes the Lucas Transmission Fix solved the problems of the replacement box. I just tried it with no expectation that it would work. I was frankly amazed when it did. I don't think its because the front prop shaft was yet to go on. That was only left off because it was late arriving from supplier to garage.
have you tried jacking up and turning a front wheel yet
 
have you tried jacking up and turning a front wheel yet
I have not done that because the problems of the replacement box have been solved. Its got full function now. But what I want to know is why ? Its almost impossible to credit that 750ml additive in 15mins solved the problems I have detailed in the original post.
 
I have not done that because the problems of the replacement box have been solved. Its got full function now. But what I want to know is why ? Its almost impossible to credit that 750ml additive in 15mins solved the problems I have detailed in the original post.
it will give more info on such
 
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