The worst job EVER on a 722.3

[Gmach]

Replacing the "O" ring on the vacuum modulator has to be the worst job I have ever had to do on this car.
The "O" ring will NOT slide into the opening straight if per-mounted on the modulator first ,the recommended way..... regardless of how much lubrication is on it.
The only way to (hopefully) seal it was to place the "O" ring in the opening first then install the modulator.
You just can't generate enough force to install it otherwise and since it's plastic you can't use a tool to push on it.
What am I missing....it should be that hard.....should it?

 

[gsxr]

This is pretty high on the list of miserable 722.3 jobs possible with the trans installed, but the B1 cover O-ring and Bowden cable O-ring are actually WORSE. Trust me.

I can't recall offhand if there is a trick to getting the vac modulator and O-ring seated properly. @JC220 ? I don't remember this being particularly difficult but I've only done it a couple of times.

 

[JC220]

This is pretty high on the list of miserable 722.3 jobs possible with the trans installed, but the B1 cover O-ring and Bowden cable O-ring are actually WORSE. Trust me.

I can't recall offhand if there is a trick to getting the vac modulator and O-ring seated properly. @JC220 ? I don't remember this being particularly difficult but I've only done it a couple of times.

I have only ever replaced the VM with the transmission removed from the car. I can't recall it being difficult but then it could be a different story changing it in car

 

[kwontumspeed]

I tried this myself on car, too. Hell F* no. Sent it to my indy, and as @gsxr touches on, had them go ahead and do the B1 and bowden while in there. Some things are just simply worth paying for.

 

[JC220]

This is when I did it last:

HOW-TO: 722.3 External Re-Seal | Transmission and Driveline

Introduction: Following on from a recent discussion here, I am re-sealing my 75k mile 722.3 transmission from my 1995 S500 in the coming week so thought I would take photos and list the goings on for others talking this in the future...

www.500eboard.co

My thoughts are - given these cars are 30+ years old now typically when a transmission starts to leak I remove it, reseal / reverse clutch replacement if needed and do the crank main seal, prop shaft bearings / mounts etc whilst in there since most all of it will be knackered by now.

This is not everyone's approach or ability I understand that. I enjoy DIY wrenching and improving my own cars so that's part of why I do it! That and preventative maintenance is key to enjoyment of the car in the long term VS dealing with the same issues repeatedly and at greater labour investment.

 

[gsxr]

Forgot to mention! To replace the vac modulator with the trans in the car, remove the rear trans mount bracket, which lets the trans drop an inch or two. The extra space makes a BIG difference in access to the modulator. Clean around the area with solvent and compressed air before removal, to avoid dirt/debris falling into the open port with the modulator out.

 

[Gmach]

So, the sad story is I had a leaky B1..the only leak at the time...and sent it to my local indy to R&R and reseal the whole transmission. Of course...that's the smart thing to do ! Problem was (as I later discovered) the indy gave the job to his apprentice who had given his 2 weeks notice and THIS was his last job before leaving !!
Anyway, I've managed to reinstall the modulator with the "O" ring installed into the transmission then inserting the modulator and with leverage using a piece of wood and the cushioning effect of a rubber bushing mount from a shock absorber where it goes into the trunk, forced the modulator in.
It worked !!
No leak..so far....fingers crossed.

 

[Duh_Vinci]

This is pretty high on the list of miserable 722.3 jobs possible with the trans installed, but the B1 cover O-ring and Bowden cable O-ring are actually WORSE. Trust me.

I can't recall offhand if there is a trick to getting the vac modulator and O-ring seated properly. @JC220 ? I don't remember this being particularly difficult but I've only done it a couple of times.

Can we also add B2 piston seal while at it? Certainly not as bad as B1, but still pita. And as for that modulator, I remember I fiddle with that thing for good 45 min when I was trying to save the original transmission! Just a pressure fitted, how hard can it be (modulator: "how hard? hold my beer")?

...I've managed to reinstall the modulator with the "O" ring installed into the transmission then inserting the modulator and with leverage using a piece of wood and the cushioning effect of a rubber bushing mount from a shock absorber where it goes into the trunk, forced the modulator in.
It worked !!
No leak..so far....fingers crossed.

Good for you, let's keep it that way!

Regards,
D