engine and drivetrain 245 Getrag 5 Speed

[ptbadboy]

Have '75 Inca with new tii spec rebuild, 292 cam, dcoe's, 3.91LSD, and much more.  Have bought another 245 5-speed  to replace one in my car.

Want to open it up to inspect the synchs, and am looking for tool #23 1 000, or similar to pull bell housing off.

On limited budget, but very good at mechanics.

 

Read that you can see the synchs through the fill hole. Yes, you can. But that doesn't tell you if they still are grabbing and spaced within tolerance .

 

Also read that you can turn the output shaft with heavy drill and shift through the gears to check synchs, but couldn't figure out a way to grab the shaft without damage. Tried tubing, but it slips(put oil in tranny first).

 

Oil had been drained, so couldn't check for big chips.

 

Also wondering if there's a gasket between the two halves, or if fine metal fit? Doesn't appear to be one.

 

If there is a gasket, is it available, and what about the synch availability?

 

Appreciate any input.

 

thanks,

don plante

[TobyB]

I don't mean to discourage you, but...

 

getting into a BMW transmission takes several tools and some patience.  

And at some point, one of the big bearings in the 5- speed was N/A-

but it might be available again.

 

My opinion is, given how hard they are to get apart and the likelihood of 

hurting them when you go in,

step 1 is install new MTL fluid, and

step 2is install transmission. 

 

 If it's good, you're done.  If it's not as bad as yours,

you can then rebuild yours while driving what you have.  And if it's a total 

mess, you can find another to try, since a completely trashed 5- speed is 

a multi- thousand dollar rebuild- and not worth the effort.  Yet.

 

It's not very hard to swap transmissions on these cars, so it won't take long.

 

I've taken several apart, and fussed with them- and that's the conclusion I've come to.

 

hope it helps,

 

t

[AceAndrew]

I'm with Toby,  But if you're equipped mechanically you should be able to mimic the needed special tools (flange-tube-threaded nut).

 

And there are some bearings that are 1mm incorrectly sized from bmw.  I wouldn't refer to etk for specific bearing numbers or sizes as they do vary without etk's knowledge.  Basically, commit to bearing sizes by checking what comes out of that trans rather than order bearings based on what is in writing.

 

Synchros are available from the dealer still, they are laso and priced around $70 each if I remember correctly.  When compressed, a good syncro will have about 40 thousandth (1mm) clearance between it and the gear.  The more they wear, the closer they get.

 

Use a very thin layer of good gasket sealer rather than a paper gasket.

Edited August 6, 2014 by AceAndrew

[Doug Riparetti]

I've never priced the cost to freshen up a G-245, any idea for labor & material?

[Chamonix72]

I've never priced the cost to freshen up a G-245, any idea for labor & material?

Metric Mechanic sells a rebuilt Getrag 245 for $2895. They also sell a "Sport OD" version for a $1000 more. I don't know what makes it more expensive though. Maybe custom ratios and/or beefier components?

[TobyB]

...and it's hard to find many people willing to open up a BMW gearbox, at least around here...

 

t

[kbmb02]

Here's Tom Cleave, at the 'hobby shop', working his magic...

 

[ptbadboy]

Terrific feedback guys. Thanks.

 

If there was any other way than actually installing to check synchs, I would jump on it. It's the diminishing space between the synch and gear that creates the grind I've learned. Andrew is right, and without running it, you have to measure that.

Pete's Gears in Hayward gave me a primer on what to look for, and said he would charge $200 or so to do it. I may take him up on it.

 

don

[cj]

Grant and Dans in Fremont does great work.

[TobyB]

Specifically, it's the wear on the cone and the synchro that closes up the gap- the gap's just

an indicator of the health of the two.

 

If you can find someone to open, check, and reassemble a BMW box for $200, do it.

 

t

[thehackmechanic]

I'm with Toby. I rebuilt one and only one gearbox -- the 242 that was in my first '02. I changed the end cover (which was cracked -- the reason for the rebuild), and while I was in there did the bearings and the synchros. It was bliss for a month. Then second gear started munching again. I'd never rebuild another. 

[glemon]

I will add to the chorus here, I have worked on cars all my adult life, engine rebuilds, carbs, suspensions, electrics, bodywork, etc.  I finally decided to do a gearbox a couple years ago, all worked fine for a while, then intermittently didn't want to go into 2nd, getting worse over time, I eventually took it apart again, same result except I didn't to wait until I had the problems with 2nd, they came right away.  I don't often say this and usually will tackle anything, but gearboxes are best left to the experts. 

[Larboard]

All, I was curious on your 5th gear upgrades. Did you cut out your gear shift hole and move it back; or shorten your shift plate? which would be better? I am well equipped for the welding, but figured all of you have gone through the conversion process and know better. Thanks.

 

Richard

[FunkyLaneO]

Since Marshall hasn't chimed in I guess someone else has to say it, do a search on 5-speed conversion in the forum, tons of info has been posted on this very subject and if you are asking this question there are alot more you are going to need answered.  btw/ the answer is we shorten the shift platform but you have alot of reading you should do before you attempt a 5 speed conversion.

[peterschop]

All, I was curious on your 5th gear upgrades. Did you cut out your gear shift hole and move it back; or shorten your shift plate? which would be better? I am well equipped for the welding, but figured all of you have gone through the conversion process and know better. Thanks.

 

Richard

 

The G245 transmission is 3.56" longer than the 4 speed transmission. One common procedure is to cut the shift platform and shift rod by 3.56", then weld every thing back together. That way the shift lever will match the gear shift hole. This is what I did. Or you can buy a custom shift platform from Ireland Engineering designed for this purpose. If you just cut a new hole in the tunnel, you will run into interference with the parking brake lever. As FunkyLane said, do a search. Tons of information on 5 speed install and many good write ups.