Getrag 245 Shift Selector problem

[Chris_B]

The seal appears to be 15x21x5mm, part no. 23128677736. Typical BMW- a gazillion part numbers superseded. 

[Einspritz]

I did a brief search at McMaster-Carr but found nothing substantive.

 

But I found here:

 

https://www.123bearing.com/section?family=4&fld_diametreinterieur=14&fld_diametreexterieur=21https://www.123bearing.com/section?family=4&fld_diametreinterieur=14&fld_diametreexterieur=21

 

You can look at the particulars to see if that will do for you. Then find a supplier convenient for you.

 

The key is in the part numbers e.g. 14X21X 6.3 being the ID, the OD, then the thickness.

 

Alternatively, convert to inches and find something that will fit, which is sometimes great for finding "in between" metric sizes.

 

A last chance possibility would be to make a solid Delrin, HDPE or somesuch with tight tolerances, although that would probably affect your shifting.

 

Somehow though, I just can't imagine that your shaft is worn at that place at all, unless something really funky is going on and the transmission internals are not really what you think.

 

That's all I got, you can take it from here.

[Chris_B]

5 hours ago, Einspritz said:

Somehow though, I just can't imagine that your shaft is worn at that place at all, unless something really funky is going on and the transmission internals are not really what you think.

 

Other than a bent shaft (not reported), why would there be a leak with new seals (2 at this point) unless the shaft was worn? The technician reports visible wear on the shaft at that point. 

 

I am looking for alternate seals, but it would think it would have to be something like 5.1 or 5.2mm to stop the leak without putting too much drag on the movement of the shaft. That would be a pretty odd size unless I can find something in inches that is close to that, 

[Einspritz]

Try pulling out the shaft and measuring with a micrometer to get an exact diameter.

Then measure the ID of the seal. Perhaps the run of seals are not up to spec.

I just don't see how a seal can wear the shaft, and if it is bent, the seal should still seal, within reason.

Are there any rough spots, like if someone gripped it with pliers?

 

Visible wear or just looking polished?

Also check that the vent hole is open, as if there is internal pressure, then the oil is going out the seal with the least resistance. Though that is a bit hard to do in situ.

 

I hate few things, but I HATE AUTO CORRECT!, Nuns taught me to spell, so I can do that just fine.I think it was Sister Carmella or Sister Mary Elephant.?

[Son of Marty]

Here you go https://www.timken.com/products/timken-mechanical-power-transmission-products/seals/redi-sleeves/ pretty complete catalog on seals and speedi-sleeves and how to fit them they will even make a custom seal for you overnight. 

[Chris_B]

Interesting suggestions, thanks. I had the tranny steam cleaned before installation. Dunno whether that would have cleared out a clogged vent. The tranny is in car. Not having had the 5 speed in the car before, I don't know how difficult it is to put eyes on the vent or stick a wire in it. 

 

I presume the shop has a micrometer to check the diameter of the shaft or ID of the seal. BTW, they said inserting a second seal reduced the leak quite a bit. Maybe cramming another one in there will do the trick. 

 

The nuns didn't do a very good job of teaching me to spell, but using apps with spell check did- after years of seeing my mistakes corrected, I have pretty much learned how to spell.  

[Chris_B]

2 minutes ago, Son of Marty said:

Here you go https://www.timken.com/products/timken-mechanical-power-transmission-products/seals/redi-sleeves/ pretty complete catalog on seals and speedi-sleeves and how to fit them they will even make a custom seal for you overnight. 

Thanks- will check this out. 

[stephers]

Sometimes the shaft will have wear marks from a bad giubo that has rubbed against it underneath on the bottom side of the shaft   check that out      after trying to fix a lot of these leaks using more than one seal over the years, the only thing in some cases is to replace the shaft 

 

Thanks, Rick

[TobyB]

Quote

 why would there be a leak with new seals (2 at this point) unless the shaft was worn? 

go back and read post #11.  The shaft's likely flopping around.

 

t

not going to type it twice, but I edited it to make it clearer.

Edited February 1, 2021 by TobyB
making the clarity

[Chris_B]

Toby, that is why god invented cut and paste. I am not familiar with the articulation point in the tranny so don't really understand how the shaft could flop around. Is there a way to test that? It is anchored securely on the shifter end, right?

 

If that is the problem, having it fixed would be a bit of a nightmare: pull the otherwise well performing tranny, find someone who will work on it, ship it somewhere and back and pay for the repair; reinstall. It used to be that you could pick up one of these trannys for a couple of hundred bucks. They seem to almost be unobtanium now. This is pretty discouraging,

[TobyB]

So, there are 2 parts to every mechanical interface, right?

 

In this case, the steel shift rod and the soft aluminum case.

The rod runs through a drilling that's just a hole- nothing special.

It's a tad loose by design to let oil get in there, because steel

and aluminum love to gall (aluminum sticks to steel) if they're not soaked.

 

But especially on the 5- speed, there is a LOT of side force on the rod when you shift into

reverse- the big push you use to get that detent to let go is multiplied by the

shift lever's leverage and applied directly to the drilling in the transmission case.

So the soft aluminum starts to deform.  I suppose it wears, too, but the couple I've

opened up look like the case itself's been distorted.

 

That doesn't really affect anything physically- the selector nose goes where it should, and it shifts ok.

But all that movement is more than the tiny little seal can handle-

as one bearing- house guy said, 'that's an ugly little thing- does it actually work?'

The seal, by its diminutive sealing depth, just isn't able to absorb much distortion.

Any smaller, and it would have had to be an o- ring. 

So when the shift shaft flops around, it lets a bit of fluid out.

 

It's just one of those 'old car' things, really.  They fixed it in the next iteration...

 

t

 

[JerryC]

Hmm... Wonder if a brass bushing made to the seal dimensions can be pushed in ahead of the second seal to reduce slop? Just sayin'. Seems like more than one thing could go wrong, but it might work.

Jerry

[Chris_B]

3 hours ago, TobyB said:

So when the shift shaft flops around, it lets a bit of fluid out.

 

It's just one of those 'old car' things, really.  They fixed it in the next iteration...

 

t

 

Got it. Seems rather pointless to replace the rod, then. This is disappointing. I hate oil leaks. My 4 speed hasn't leaked a drop during the last 10 years. 

[tech71]

3 hours ago, Chris_B said:

My 4 speed hasn't leaked a drop during the last 10 years. 

Really? not one drop ever? From the entire transmission?  Thats....unlikely uh, I mean amazing!

I hate oil leaks too but after several years maintaining Blackhawk helicopters, an occasion dribble, leak or seep out of my 02 just makes me smile. 

Edited February 3, 2021 by tech71

[Chris_B]

Ask me no questions and I'll tell you no lies. Seriously, I had the tranny professionally rebuilt with new gaskets/seals, and told the shop that I didn't want any stinking oil leaks. They did a good job, except the second gear synchro is a bit crunchy when the tranny is cold. In fact, I don't have any, from the motor, tranny or diff. The spot where I park my car and have for the last 15 yrs. is clean.  If I had the car here, I would send a pic.