4HP20 need opinion..

toh · Post by **toh** » 26 Oct 2010, 11:33

http://www.youtube.com/watch?v=VvYkxhoJ ... re=related

http://www.youtube.com/watch?v=5Dgqdtqy ... re=related

this is my 4HP20 gearBox, i pulled it down on last day to check.

but this what i found.

What do you think?

Post by **CitroJim** » 26 Oct 2010, 17:44

Oh dear Toh, That's serious

My diagnosis is that the output bearings have failed.

I have been there, with the exact same fault.

You'll need to completely strip the F Brake to expose the bearings and you may find something like this:

And

Likely the F Brake housing will be damaged too.

To strip the F Brake you'll need special tools but for now, you can have a look at the bearings by removing all the F Brake plates and then looking below the special nut. You'll need a special tool to get it undone for further inspection.

This is the special tool (home-made):

And this is the tool in use. The nut is VERY tight..

Lock the gearbox using the park pawl to undo the nut.

See my rebuild guide for more pictures.

The reason for the failure will be lack of oil pressure and likely a damaged torque converter. Is the torque converter neck bearing OK?

Let us know what you find...

toh · Post by **toh** » 27 Oct 2010, 06:19

hi, CitronJim.

refer to last clutch set replacement.
Then, my PUG 406 was in jerk. gear changing is rough, not smooth as usual.
i drove it by using only 3rd gear.but sometime need to change to 1st or 2nd.

every time of gear changing, the jerk occur.
i ran a car like this for awhile, around 1500 km.

last weekend, i got 3 days off. then i opened the gearbox.

The main object is to fix the jerk problem.

Haha..

i need opinion because i've never open a good condition gearbox.
Then, i am not sure the video as you see is normally or not.

about the neck of torque converter bearing let me check.

appreciate for clear picture.

Post by **CitroJim** » 27 Oct 2010, 10:37

The two videos really helped to explain the problem and a possible diagnosis Toh

What you see is not normal at all.

I think that after dismantling the F Brake, the cause of the problem will become clear.

toh · Post by **toh** » 27 Oct 2010, 17:13

i will dismantle all on this saturday. and i will share all.

JiM, with honest. Do you get all what i am trying to say?
i mean, in the message above.

because i'm not sure that my english is clear or not Ha haha

anyway,Thank you

toh · Post by **toh** » 28 Oct 2010, 14:32

this might what you mean the neck of Torque Converter,

Post by **CitroJim** » 28 Oct 2010, 20:36

That's exactly Toh

And I'm pleased to say it is in good condition. No damaged neck bearing there

If the bearing had been damaged, you've have found great difficulty in removing the torque converter from the gearbox as the seized bearing would have prevented it coming off.

Had it been bad, you'd have seen the bearing seized to the neck like the one in the picture below...

This was the bearing after I managed to pull it off the neck...

You can see where it was spinning in its housing...

I keenly await pictures of your output shaft bearings below the F Brake

toh · Post by **toh** » 31 Oct 2010, 15:22

Jim,

This is me Brake F

toh · Post by **toh** » 31 Oct 2010, 15:24

sorry, too big pic.

I hope Jim can see the line on the line disc clearly.

and this is a Brake F inner disc carrier

toh · Post by **toh** » 31 Oct 2010, 15:28

Jim, i am facing the problem with posting picture.

you can take a look over here http://ezymcu.blogspot.com/2010/10/surv ... ake-f.html

toh · Post by **toh** » 31 Oct 2010, 15:40

what do you thing about inner copper.?
is it too loose?
have you?

Post by **CitroJim** » 31 Oct 2010, 16:14

Hi Toh,

Looking at the pictures of the F Brake hub shaft and the phosphor bronze ("inner copper") bearing, both these are very badly worn. I would suggest that the F Brake basket and the output shaft is worn beyond reuse.

I watched the video and the noise that is made as the differential is rotated is not normal.

There is a serious problem with the output shaft and to find out more then you must remove the big slotted nut and inspect the big taper roller bearing you will find underneath.

Could you feel "play" on the big slotted nut to suggest that the bearing has failed?

As explained before, the slotted nut is VERY tight and needs a special tool to undo it. It is tightened to 250 NM and I used an impact gun to undo one.

To extract the output shaft and bearings, the F Brake needs to be dismantled by firstly compressing the diaphragm spring using a tool like this:

In this way:

To enable the spring retainers to be removed:

Then you can carefully remove the Brake F piston using compressed air:

be sure to go gently with your hand on the piston so that it does not fly out.

Then you can remove the Brake F piston housing after removing the radial bolts. be very careful here not to scratch the side of the housing as you undo the bolts. I wrap the socket in adhesive tape.

Once all the bolts are out, and the slotted nut is removed, the piston housing may be lifted and this will then fully expose the output shaft and it's top bearing. You should eb able to see what has happened.

Please be warned Toh that this is not an easy job to do. In particular, be very careful with the big slotted nut and do not try any bad ways to remove it!

You must consider why this has happened and my belief is a lack of lubrication. Next, you must disassemble the oil pump and check its condition and when reassembling, replace the oil filter.

Has the gearbox always been filled with the correct Esso/Mobil LT71141 ATF?

toh · Post by **toh** » 01 Nov 2010, 02:39

That's too much job to do.

here is my Gear oil,
they said this ATF can replace esso LT11714
i also take a look on the other parameters. it has a little bit difference.

Post by **CitroJim** » 01 Nov 2010, 06:00

Oh no

That stuff is DEXRON III and NOT suitable for a 4HP20 at all...

I'm not saying it has been totally responsible for killing your gearbox Toh but it has certainly done it no favours..

As we repeat on here many, many times, the ONLY ATF for a 4HP20 is Esso/Mobil LT71141. It has no equivalent and using anything else will shorten the life of the gearbox. That there is considerable wear on the most stressed part of the gearbox points to a lubrication failure and the use of DEXRON is a major suspect.

Yes, getting to the output shaft bearings is the hardest job in a 4HP20 by far.

Your best option now may be to find a complete spare gearbox...

dieselnutjob · Post by **dieselnutjob** » 01 Nov 2010, 09:49

I looked on the Valvoline european site at http://www.valvolineeurope.com
on that site they are advertising MaxLife™ ATF with

MaxLife ATF is the only ATF formulated for vehicles with over 100,000 kilometers.

Sure that is just a flat out lie?

Performance Levels/Approvals > MaxLife ATFGM Dexron III, IIE, IID; FordMercon, Mercon V; Allison C-4,TransSynd*, TES-295; BMW LT 71141, LA 2634, MAN 339type F, Mazda*, Mini CooperCVT EXL 799, Toyota T, T-11,T-IV; Chrysler ATF+3; MitsubishiDiamond SP-II, SP-III; HondaATF-Z1, MB Approval 236.1,236.2, 236.6, 236.8, 236.9,236.11; Nissan D,J,K,-matic,Volvo 1161521, 1161540;Audi G-052-0250-A2,GM9986195, ZF-TE-ML-14B,16L, 17C, JWS 3309, Voith G607, 1363; KIA SP-II, SP-III;Suzuki*, VW TL 52162

Approved by who?
Maybe a complaint to the Advertising Standards Agency should be made.