w124 722.501 gearbox flaring.

boomtings

Active Member
Joined
Aug 23, 2009
Messages
210
Location
London
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95 e320 cabriolet ,93 300te_24v Turbotechnics
Hi.

My 300 24v TE is reving between gear changes. Its also slow to engage into drive and reverse I assume this is why it flares. I've changed fluid and filter and although it feels better it still misbehaves.

The cars a Hughes TT and I'm pretty sure that a vac line is disconnected to provide firmer gear changes.

Its a 5 speed gearbox.

My questions are:

If this going to require a rebuild.

Can I replace my gearbox with any 722.5xx box. Or do I need the exact part number as a replacement.

Can I swap a 4 speed from a 320ce that I have in as a temp/permenant replacement.

Ive read that stand alone controllers exist that allow newer Mercedes 722.6 boxes to be also fitted. This seems like the adventurous path to go down.

Any advice appreciated.
 

WDB124066

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Apr 17, 2009
Messages
6,176
Car
1996 E320 Sportline Cabriolet x 2
Sounds like an internal oil pressure problem...??

If the vacuum line disconnects I was under the impression it made shifts firmer not weaker.

If it was 2-3 upshift only there is a spring kit you can install - I have the part number if you are interested but from the sounds of it this is not a fix for your situation.

If it wasn't slow to engage forward and reverse I'd say try turning up the modulating pressure on the side of the box - but I don't think from the sound of it that this will solve the slow to engage problem and may make things inside worse.

Try contacting the Classics Centre in Fellbach directly, using google search, and email them for an exchange price, they can be very competitive price wise especially if you want to keep the car, as everything is replaced then the unit is fully tested on a test rig. You simply cannot get that done locally for the same price.

You may find it is even cheaper than fitting alternative boxes as this can be a little tricky unless you use somebody who has actually done this before.
 
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carat 3.6

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May 11, 2011
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Buckinghamshire, yuppie central 1985.
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96 e300d, 88 w124 superturbodiesel, 90 bmw E30 v8, + "others"
Hi.

My 300 24v TE is reving between gear changes. Its also slow to engage into drive and reverse I assume this is why it flares. I've changed fluid and filter and although it feels better it still misbehaves.

The cars a Hughes TT and I'm pretty sure that a vac line is disconnected to provide firmer gear changes.

Its a 5 speed gearbox.

My questions are:

If this going to require a rebuild.

Can I replace my gearbox with any 722.5xx box. Or do I need the exact part number as a replacement.

Can I swap a 4 speed from a 320ce that I have in as a temp/permenant replacement.

Ive read that stand alone controllers exist that allow newer Mercedes 722.6 boxes to be also fitted. This seems like the adventurous path to go down.

Any advice appreciated.

Iirc Hughes do change the shift points, but didn't disconnect any of the vac lines. That could be related to your problem.

You can fit the 4 speed if you want to, but if it's a permanent swap you will need to swap the diff to match.

The 722.6 swap is possible, but can require alot more work than it first appears.

If I was in your position and your gearbox did need replacement, I would either find a replacement 722.5, or be tempted to go for the 4 speed from a 280 w124.

But then if it was me it would have a clutch pedal!:devil:
 
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boomtings

boomtings

Active Member
Joined
Aug 23, 2009
Messages
210
Location
London
Car
95 e320 cabriolet ,93 300te_24v Turbotechnics
For some reason I was unable to reply using my phone.

I thought id inspect vacuum lines from WDB124's reply.

Today I went under and found a green vacuum line which was disconnected and I connected it to my inlet manifold. It seems the gear box starts in 1st gear every time and the car feels a lot more responsive. Almost as if the cars allways in kickdown!

The gearbox is still flaring between 2-3(milder) and 3-4 changes but definitely feel a lot smoother.

Can someone confirm if they know where the last vacuum outlet on the inlet
manifold (near oil filter) is suppose to be connected to.

Mine was connected to a white vacuum line that ended unconnected near where I found the Green line (just below the oil housing towards gearbox).

Im planning to visit a gearbox specialist on Wednesday.

Carat you now have me thinking/dreaming about having a manual gearbox:doh:
 
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