gear box, renewing gaskets and oil seals

[deQuincey]

hi

if you happen to find a drop of gearbox oil in the garage, it is only a question of time to accomplish this little mission

so some comments and some photos may help you

if your slave clutch cylinder is the old type, you can remove the gear box without removing the engine bellhousing, this is very convinient

gearbox front

rear

gasket and seals set

front side : remove bolts

different size of bolts, please mark their position

take care of shims:

remove gasket

check blue manual: seal position: offset is negative -4,5mm

old seal in hand, new in its position:

use the old seal to help you with the introduction of the new one, use the seal as a dumm piece and hit this old one with the hammer, this will spread the force evenly, do not use and grease to help the new seal slip onto its final position, that grease will cause you problems in the future, it is a hard job, and it is harder than usual because you need to accomplish a final offset position

 

[deQuincey]

once this is done

we continue, clean and prepare, the holes for the bolts use to be very dirty, but you can not clean them with any product that may introduce dirty or liquids inside (the hole is not closed and communicates with the interior of the gear box)
preinstallation check

place the gasket and some sealant:

remember, you must leave the sealant to dry some minutes before placing the other part, and some more minutes before applying the specified torque

a special condition in this case, must seal the bolts

check the manual for the specified torque:

and apply it

front is finished

 

[deQuincey]

seal caps

all around the gearbox there are caps that you must seal

it is a boring process, you must position the cap horizontally, fill it with the sealing compound, and wait until it cures,. and then move onto the next caps

 

[deQuincey]

rear side

not as many pictures, but more straigth forward

first you must undo the collar nut, for that you must dissasemble the special blocking washer first, follow the instructions on the manual

remove the nut with a 30 hexagonal extra long vase, and remove the three legged part with an extractor,

then remove the seal and place a new one until it flush, use a hammer and a wood piece to hit the seal evenly

then place the three legged thing,

VERY IMPORTANT, PUT SEALANT INTO THE SPLINES, OBVIOUSLY IF YOU DO NOT CLOSE THE SPLINES OIL WILL COME OUT THROUGH THEM


the nut and finally the special washer, and you are done !

regards

 

[Stevehose]

I did this also - did you replace the shift linkage seal? This was leaking on mine and was challenging to remove without damaging the aluminum housing - I used a seal pick from Harbor Freight.

 

[deQuincey]

I did this also - did you replace the shift linkage seal? This was leaking on mine and was challenging to remove without damaging the aluminum housing - I used a seal pick from Harbor Freight.

hi steve
mine was not leaking, but as i have the replacement i wil appreciate your help with a little explanation of how you proceeded
a photo of the tool you mention will be very helpful too
regards

 

[johanaxelson]

Wow, thanks.

 

[DaSurfa]

My current 4 sp is leaking alittle and I have a 5 sp sitting in my garage.
This looks like a fun project.

Where can I find this gasket kit and what are the part numbers for both 4sp and 5sp?
What kind of sealant are you using?

Thanks,
David

 

[Luis A.]

Nice job DQ. Is the seal set available complete from BMW or you just buy each piece separately?

 

[deQuincey]

Nice job DQ. Is the seal set available complete from BMW or you just buy each piece separately?

hi luis
i went separately one by one, just check the drawings in the realoem, or similar and order them from bmw

 

[Stevehose]

Sorry, been digging out from a hurricane (the storm, not the drink). I bought my seals all from RM European, there were 2 different manufacturers of the shift seal so I bought 2 each to check quality and have a backup. The seal can be difficult to get out, some people say just tap the old one in to make room for a new one and since I couldn't get mine out, this is what I did. Don't do this-it may not leave you enough room for the second one and/or will mangle it upon install. The seals also damage easily when installing. Since my first attempt leaked I used these to get it out:

They are called "seal picks" (oil cap for size reference) and are available from different sources in different shapes. I tried the right angle one to reach in and pull but it wouldn't budge it out. Maybe yours will come out with this. I ended up tapping the straight one carefully into the inside of the seal through the metal frame then leveraging/tapping it out with a hammer-pry one side up a little then tap another side and slowly work it out. You have to be very carefull because the aluminum scratches easilly. Once removed I put a very light coat of gasket sealer on the new seal and tapped it in with a long socket that matches the diameter of the seal and fits over the shift rod. I mangled it on my first attempt - if it is not started at a straight alignment it will go in crooked and you're screwed. Tap in very lightly and slowly, keeping it even on all sides until flush with the tranny case. Hasn't leaked since.

hi steve
mine was not leaking, but as i have the replacement i wil appreciate your help with a little explanation of how you proceeded
a photo of the tool you mention will be very helpful too
regards

 

[deQuincey]

thank you very much steve
now i perfectly understand it
are you ok?
has the danger finished ?
regards

 

[Stevehose]

Yes thanks, electricity back on and the coupe safe in the garage. Just a lot of clean up to do.

thank you very much steve
now i perfectly understand it
are you ok?
has the danger finished ?
regards

 

[sfdon]

Shift seals are tough! I always order extras because I wreck them so often.

 

[deQuincey]

as to october the 29th, gearbox is reserved

as finally i will not use this gear box in my car, because the noise i experienced was comming from the transmission, this one is for sale, please if interested contact by mp, thanks

together with the gaskets and seals i will renew all the nuts, washers and bolts that i am going to remove

that inlcude the exhaust, transmission, and gear box itself

many of those bolts and nuts are rated 10.9 or C10 respectively, and it is very difficult to find such a high specs quality material in bichromat finishing just on the shelf (the guy collected all the material in 5 minutes after giving him the list !)

here is the result of yesterdays shopping, isn`t it a beautiful view of goodies ?

 

[teahead]

Old thread resurrection.

Anyone know the part # for the rear output seal?

Can't find from the below info:

Manual Transmission | BMW 5' E12 528i M30 Europe

Manual Transmission, BMW 5' E12 528i M30 Europe

bmwfans.info

 

[sfdon]

Try rmeuropean

BMW Seal - Output Shaft (40 X 55 X 8 mm) 23121205342 - ELRING KLINGER