722.5 transmission oil pump rebuid DIY

34634 Views 10 Replies 6 Participants Last post by farmerpete-aust, Jul 20, 2016

symbolic95

Discussion Starter · Mar 29, 2008

If you have an oil leaking from the front of the transmission ,you will have to rebuild ,or replace oil pump.New pump costs around $300-$400,rebuild-gaskets around $130.

1. Remove transmission http://www.benzworld.org/forums/w140-s-class/1368666-transmission-removal-m104_s320.html

2.remove pump bolts,note that theres two vacant holes on each side.
3.Screw two bolts into threaded holes and use them to pull out front pump.

Auto part Rotor Clutch Clutch part Bearing

INSTALLATION NOTE:
Clean surfaces,replace pump gasket,do not use any sealant.Use non hardening sealant and torque bolts to 13Nm.

4. Remove two Teflon rings.
INSTALLATION NOTE:
Insert two new Teflon rings with TRANSMISSION ASSEMBLY GREASE.
Assure that the ring gaps remain together.

5.To remove spring plate and springs(total number 20) ,you will need to make a tool.
I used 3" in diameter pipe(from your local plumbing store-Home depot),and later i did cut a window to get access to a snap ring,12" bolt with washers and nut, and any kind of metal plate (drill a hole for bolt).

6.Clamp,until snap ring is exposed,remove snap ring ,remove plate and springs.
I found that the best DIY'er friends are white paint-when disassembling something,to mark positions,and zip bags,to keep bolts,nuts,washers ;
in this case springs from ....

7.Mark and pull out B3 piston.
INSTALLATION NOTE:
Replace Lip seals,apply oil to the seals,make sure that the lip pointing towards the rear.
When inserting piston make sure pin and the hole coincide,make sure not to crimp seals,when installing piston.

8.Remove pump front cover.
INSTALLATION NOTE:
tighten bolts to 20NM

Auto part Rotor Clutch part Locking hubs Wheel

9.Top and bottom of pump gears differs,make sure you reinstall them right ,bevel points towards radial seal.
Install new radial seal(red seal in the first picture-front pump seal)

Clutch part Auto part Rotor Clutch Disc brake

10 Replace pump O-ring by installing it into the groove.

.
Good luck Vladimir.

See less See more

Save

Reactions: 5

1 - 11 of 11 Posts

Brett San Diego

· #2 · Mar 29, 2008

More nice documentation. First I've seen anyone do some transmisson DIY work. Cool.

Brett

Save

symbolic95

Discussion Starter · #3 · Mar 29, 2008

i searched interent and could not find anything,even guys from w126 forum have nothing there,all you read, is that they pay someone for rebuild .
transmission shop quoted $850 just for the front seal.

I feel that one day i'll have to dig a little bit deeper into transmission,hope this day is not around the corner

Save

ch.1953

· #4 · May 8, 2015

Very helpful; MAVA rocks - thanks Martin...

Save

Reactions: 1

Stevewelsh

· #5 · May 14, 2016

Where can the replacement 20 springs and spring plate b purchased?

Save

MAVA

· #6 · May 14, 2016

Stevewelsh said:
Where can the replacement 20 springs and spring plate b purchased?

The dealer and What ever it takes Transmission(Wittrans.com). I believe the 190 has 722.4

Martin

Save

farmerpete-aust

· #7 · Jul 16, 2016

Question on sealant

INSTALLATION NOTE:
Clean surfaces,replace pump gasket,do not use any sealant.Use non hardening sealant and torque bolts to 13Nm.

Hi from Australia
I was going to wet both sides of pump gasket with trans fluid and bolt up?
Sealant or no sealant?
I was careful not to hack up the gasket mating surface with the razor blade but there are a few very minor scratches on the aluminium so I think a non hardening sealant would be advisable ???

I'm also needing the torque specs for the flex-flywheel bolts

Kudos to all the clever buggers / photographers on this forum
Cheers

See less See more

Save

Reactions: 1

MAVA

· #8 · Jul 17, 2016

farmerpete-aust said:
INSTALLATION NOTE:
Clean surfaces,replace pump gasket,do not use any sealant.Use non hardening sealant and torque bolts to 13Nm.

Hi from Australia
I was going to wet both sides of pump gasket with trans fluid and bolt up?
Sealant or no sealant?
I was careful not to hack up the gasket mating surface with the razor blade but there are a few very minor scratches on the aluminium so I think a non hardening sealant would be advisable ???

I'm also needing the torque specs for the flex-flywheel bolts

Kudos to all the clever buggers / photographers on this forum
Cheers

Welcome to the forum,

Really their is no need for a sealant, but what I do is clean out the bolt holes with a cotton swab with denatured alcohol two to three times. I do this for the pump holes on the inside too. I clean the bolt threads with alcohol-I pinch the threads with my thumb nail and middle finger nail with a paper towel. I do this twice. Yes Yes it is tedious, but remember the torque is low on those bolts, and the LocTite has to really Grip(the instructions say the surfaces have to be clean :grin ). I use locTite for high Vibration and High Heat.. I clean each surface(bolts too-new paper towel) with a new piece of paper towel. I do two applications, and wipe it dry-not letting it evaporate. I alcohol wipe the gasket on both sides too. I do a five step torque on all the bolts in a star pattern,and I torque them 20% more.

I never use razor blade to clean the surfaces. A special cleaner is made for that...

I will get back to you on the torque converter bolts, and those bolts need to be new too.

Martin

See less See more

Save

farmerpete-aust

· #9 · Jul 17, 2016

Cheers Martin
I suddenly deciphered that the non harden sealant is on the bolts only.
The flywheel bolts are tighten to yield then? Wish they'd mentioned that at the spare parts counter

Save

MAVA

· #10 · Jul 17, 2016

FlyWheel to Torque converter is 50Nm(37lbs) try to do a three-step

Flywheel to engine is 45Nm(33lbs) +90 degree's. Try to do three step on the bolt torque, and a two step on 90 degree's

All these bolts need to be new bolts

The LocTite I use is 272

LOCTITE 272 - Threadlocking methacrylate adhesive - Loctite

I use transmission assembly grease to hold the teflon seals as they are super easy to crush...Those springs and the plate. I suggest you replace them as they can spring-out

http://www.benzworld.org/forums/w14...hic-b3-piston-failure-tranny-rebuildable.html

I have one tranny I rebuilt that the old springs lasted 10k all because I think the plate with the dimples got bent on installation, or the springs were weak.... These old trannies(722.3-722.5) has this. The 722.6 and 722.9 do not way easier to rebuild..

All the best,

Martin

See less See more

Save