Autobox problems - possible cause? - Page 4

beinet1 · 22nd August 2012, 16:24

Hi all,

Parts recieved today. It took less than 48 hours from order was placed at Automatic Choise Ltd. before it was delivered at my front door! a total of £130 including shipping to Norway, toll charges an Norwegian VAT. I also picked up 6 litres of Texaco N402 compatilble ATF from the local auto warehouse for £37 pr. 4 litre. I guess I start the job in the beginning of next week. I give it 50/50 chance to success

fingers crossed...

ATF specification:

rover54 · 22nd August 2012, 17:12

Quote:

Originally Posted by beinet1

Hi all,

Parts recieved today. It took less than 48 hours from order was placed at Automatic Choise Ltd. before it was delivered at my front door! a total of £130 including shipping to Norway, toll charges an Norwegian VAT. I also picked up 6 litres of Texaco N402 compatilble ATF from the local auto warehouse for £37 pr. 4 litre. I guess I start the job in the beginning of next week. I give it 50/50 chance to success

fingers crossed...

ATF specification:

If you are doing the reverse piston and also changing the oil and the solenoids check out; I would give it better than 50/50, maybe 95/5 as having read quite a number of threads on this suject, it appears to be a sucessful repair proceedure.

The lable is incredibably detailed regarding alternative manufactures coding for this oil. It will enable us to track down the cheapest source.

beinet1 · 22nd August 2012, 18:09

Quote:

Originally Posted by rover54

If you are doing the reverse piston and also changing the oil and the solenoids check out; I would give it better than 50/50, maybe 95/5 as having read quite a number of threads on this suject, it appears to be a sucessful repair proceedure.

The lable is incredibably detailed regarding alternative manufactures coding for this oil. It will enable us to track down the cheapest source.

Hi,

Regarding the oil, I had a long search for the rigth kind of oil when I had a VW passat auto for some years ago as VW only specified its own part number for the oil which was far to expensive. I found out that this was a LT 71141 ol which also was used on lots of other cars which was sold under their genuine part number. The same seems to apply to the ATF fluid specifed for the Jatco box. Just look at the specification label on this oil. This oil is sold through one of scandinavias bigges auto warehouse under its own name, but I don`t know where it is sourced from. As long as I got it for a resonable price and it have the correct specification, I am happy

Good to know that you give this a lot more than 50/50 chance

I have only read a few threads about the issue and I have seen both success and failure

beinet1 · 27th August 2012, 04:18

Hi all,

Just a little update...

I startet the job yesterday eventing. Got the car up on ramps, removed undertray and inner wheelarch. Oil drained. I got approx 4 liter out of the box. It did not smell any well. It was blackish and smelt burned. Gearbox lowered by loosing the gearbox mount but subframe was not disturbed. End cover removed. I noticed a build up of swarf/metal particles on the RPM sensor. The smelly oil and the swarf found gave not any good "stoomach-feeling". Main drum removed out from the box and put on my workbench for dismantling. For some reason, I did not need to remove the large internal circlip to remove the outermost flange/gearing on the drum the way it was carried out in the procedure. IT seems to me that there are something wrong here. Need to investigate this some more.... The rest of the drum was dismantled according to procedure and a cracked reverse piston was revealed! I will do some more inspection/cleaning before I start to put things back again. For what I have seen so far, I will give this 30/70 chance to success :s This work took me 2 hours.

P.S.
The area were I seems to have issues, is related to the reverse pressure/friction plates and the circlip which retains these. Seems to be excessive wear here. More to come......

Here are some pics:

Old ATF fluid

End cover removed

Main gearing drum removed

RPM sensor inside gearbox

Cracked reverse piston

Main drum components on workbench

SD1too · 27th August 2012, 07:20

Splendid work Einar!

And excellent pictures too. It's worth reminding ourselves here that the fault was that the transmission was slipping out of some forward gears, and you have found a cracked reverse piston (it doesn't look much of a crack does it). So Crofts was absolutely correct; see post no. 2.

Simon.,

beinet1 · 27th August 2012, 09:27

Hi

OK, trying to summarize what I have seen so far and plan the way ahead. The cause of the problem i without any doubt a cracket reverse piston. There is excessive wear on the reverse pressure/friction plates probably due to slipping here due to low "holding force" caused by a leaking/cracked reverse piston. It seems that I have to renew the pressure/friction plates for the reverse. Does any know what thickness these shall be when new?? What about the pressure/friction plates for the high clutch? Migth these be worn to? How to check??
I will not give this up without a try

Thanks for all advice so far

SD1too · 27th August 2012, 10:44

JPAT will be able to answer those questions for you, and possibly Sussex Autos will as well. It's a public holiday in England today though.

Keep up the good work.

Simon.

beinet1 · 27th August 2012, 11:38

Quote:

Originally Posted by SD1too

JPAT will be able to answer those questions for you, and possibly Sussex Autos will as well. It's a public holiday in England today though.

Keep up the good work.

Simon.

Thanks

Ahh..... that`s why the suppliers don`t answer my price enquiries today

Lucky you, I am sitting in my office and looking at the great wheater outside today...... :s

beinet1 · 27th August 2012, 19:11

Hi,

The last observation:
The circlip that retains the reverse pressure/friction plates have for some reason lost its spring effect and was found out of its groove. pressure/friction plates are deformed. Seems like I need to renew these parts and things will be ready for rebuild.

Deformed circlip

Deformed reverse pressure/friction plates

crofts · 28th August 2012, 07:13

Quote:

Originally Posted by SD1too

Splendid work Einar!

And excellent pictures too. It's worth reminding ourselves here that the fault was that the transmission was slipping out of some forward gears, and you have found a cracked reverse piston (it doesn't look much of a crack does it). So Crofts was absolutely correct; see post no. 2.Simon.,

Thanks Simon. Having never experienced a problem with my box (till now-pray!) I wonder each time I comment whether I am going to be proven incorrect and should therefore 'put a sock in it' & keep quiet ! However, here we go again, with one of the 3 frequently occuring problems. (fluid, solenoids, cracked piston)
Like you, I am amazed that such a faint hairline crack can cause such a problem. Assume it is just the extreme hydraulic pressure that creates the problem

22nd August 2012, 16:24	#31
beinet1 Posted a thing or two Rover 75 2.0 V6 Auto Join Date: May 2011 Location: Sandnes - Norway Posts: 1,560 Thanks: 64 Thanked 283 Times in 174 Posts	Hi all, Parts recieved today. It took less than 48 hours from order was placed at Automatic Choise Ltd. before it was delivered at my front door! a total of £130 including shipping to Norway, toll charges an Norwegian VAT. I also picked up 6 litres of Texaco N402 compatilble ATF from the local auto warehouse for £37 pr. 4 litre. I guess I start the job in the beginning of next week. I give it 50/50 chance to success fingers crossed... ATF specification: Last edited by beinet1; 22nd January 2018 at 19:03..

27th August 2012, 04:18	#34
beinet1 Posted a thing or two Rover 75 2.0 V6 Auto Join Date: May 2011 Location: Sandnes - Norway Posts: 1,560 Thanks: 64 Thanked 283 Times in 174 Posts	Hi all, Just a little update... I startet the job yesterday eventing. Got the car up on ramps, removed undertray and inner wheelarch. Oil drained. I got approx 4 liter out of the box. It did not smell any well. It was blackish and smelt burned. Gearbox lowered by loosing the gearbox mount but subframe was not disturbed. End cover removed. I noticed a build up of swarf/metal particles on the RPM sensor. The smelly oil and the swarf found gave not any good "stoomach-feeling". Main drum removed out from the box and put on my workbench for dismantling. For some reason, I did not need to remove the large internal circlip to remove the outermost flange/gearing on the drum the way it was carried out in the procedure. IT seems to me that there are something wrong here. Need to investigate this some more.... The rest of the drum was dismantled according to procedure and a cracked reverse piston was revealed! I will do some more inspection/cleaning before I start to put things back again. For what I have seen so far, I will give this 30/70 chance to success :s This work took me 2 hours. P.S. The area were I seems to have issues, is related to the reverse pressure/friction plates and the circlip which retains these. Seems to be excessive wear here. More to come...... Here are some pics: Old ATF fluid End cover removed Main gearing drum removed RPM sensor inside gearbox Cracked reverse piston Main drum components on workbench Last edited by beinet1; 22nd January 2018 at 19:03..

27th August 2012, 07:20	#35
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,368 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Splendid work Einar! And excellent pictures too. It's worth reminding ourselves here that the fault was that the transmission was slipping out of some forward gears, and you have found a cracked reverse piston (it doesn't look much of a crack does it). So Crofts was absolutely correct; see post no. 2. Simon., __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

27th August 2012, 09:27	#36
beinet1 Posted a thing or two Rover 75 2.0 V6 Auto Join Date: May 2011 Location: Sandnes - Norway Posts: 1,560 Thanks: 64 Thanked 283 Times in 174 Posts	Hi OK, trying to summarize what I have seen so far and plan the way ahead. The cause of the problem i without any doubt a cracket reverse piston. There is excessive wear on the reverse pressure/friction plates probably due to slipping here due to low "holding force" caused by a leaking/cracked reverse piston. It seems that I have to renew the pressure/friction plates for the reverse. Does any know what thickness these shall be when new?? What about the pressure/friction plates for the high clutch? Migth these be worn to? How to check?? I will not give this up without a try Thanks for all advice so far Last edited by beinet1; 27th August 2012 at 10:07..

27th August 2012, 10:44	#37
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,368 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	JPAT will be able to answer those questions for you, and possibly Sussex Autos will as well. It's a public holiday in England today though. Keep up the good work. Simon. __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

27th August 2012, 19:11	#39
beinet1 Posted a thing or two Rover 75 2.0 V6 Auto Join Date: May 2011 Location: Sandnes - Norway Posts: 1,560 Thanks: 64 Thanked 283 Times in 174 Posts	Hi, The last observation: The circlip that retains the reverse pressure/friction plates have for some reason lost its spring effect and was found out of its groove. pressure/friction plates are deformed. Seems like I need to renew these parts and things will be ready for rebuild. Deformed circlip Deformed reverse pressure/friction plates Last edited by beinet1; 22nd January 2018 at 19:04..