280/5 Transmission on the Bay...

[Roku35]

280/5 Transmission on the Bay...

http://cgi.ebay.com/ebaymotors/BMW-Getrag-280-Transmission-Close-Ratio-M5-M6-e28-e24_W0QQcmdZViewItemQQhashZitem35a7b57544QQitemZ23 0446953796QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAcce ssories#ht_500wt_1133

Any comments or interest?

[bimmerjo]

I'd be more than happy to trade my e30 with a clean and clear title for....

[JRanmann]

Anyone?

Would this be an appropriate replacement for my 260 and will it work with the proper length (shortened) driveshaft and LSD or is there more to this story?

I hope it actually is in good shape...how does one tell when out of the car?


Ran

[Layne]

I need it, but who knows if it works any better than what I have...

[alpinacsi]

Doug is a reputable seller and is very familiar with the m5/m6. With that said and description given of the the trans, I would expect no hidden issues or misrepresentations. But it is a used part and anything can happen.

Can it be used to replace a 260 trans? Yes. Is it the appropriate replacement? No.

[bimmerjo]

What are the torque limitations of the 280?

[e24mpwr]

Doug is a reputable seller and is very familiar with the m5/m6. With that said and description given of the the trans, I would expect no hidden issues or misrepresentations. But it is a used part and anything can happen.

Can it be used to replace a 260 trans? Yes. Is it the appropriate replacement? No.

A big +1 to all this.


What are the torque limitations of the 280?

There are 280's mated up to M88/S38's running well into the 400HP's. They tend to have weak syncros IMHO.

[detroit635csi]

if i didnt just buy all the parts i just bought..

[Layne]

if i didnt just buy all the parts i just bought..

You realize this is just a regular M6 transmission, nothing that would do a 635 any good. BMW called it "close ratio", but it is not the dogleg transmission.

With Todd and Lee vouching for the guy, I'm giving it some thought. Was figuring on rebuilding mine at some point.

[Seeker]

I again wonder if a standard 635 driveshaft would properly match up to the 280.. as in simply PnP.
Or would you need to either get a M6 DS or have the 635 DS altered?


From what I've ascertained, this trans really does no performance enhancements for a NA M30. That basically its good for keeping an M6 to original spec.
Correct me if I'm wrong...

[Bentsdl]

Yes, from what I've heard it's more fragile than the 265's and extremely expensive to rebuild. Also it's more expensive too buy in the first place.

[Layne]

I again wonder if a standard 635 driveshaft would properly match up to the 280.. as in simply PnP.


From what I've ascertained, this trans really does no performance enhancements for a NA M30. That basically its good for keeping an M6 to original spec.
Correct me if I'm wrong...

1) Absolutely not 2) true


Yes, from what I've heard it's more fragile than the 265's and extremely expensive to rebuild. Also it's more expensive too buy in the first place.

All true

[Seeker]

wow...

so really the only reason its more expensive is because its rare to get ahold of and only sought after to keep an M5/M6 to original spec.

thats almost funny as hell that the 265 can take a beating better than a 280.


I recalled this fella changing out his 280 for a 265 on his E28 M5

http://www.mye28.com/viewtopic.php?t=59684

he said:


There is a lot of conflicting information out there about the compatibility of a Getrag 265 and a Getrag 280. I measured both and the 265 is about 6mm longer at the output flange and about 10mm longer at the selector shaft. The standard E28 M5 driveshaft will work with the 265. The center bearing has room to move because the mounting bolts are in slots.

so evidently the M5/M6 DS can work with the 265.. but what about the 635 DS working with the 280 if one truly tried this? I'm again guessing it's not possible the other way around?


sorry for the redundant questions.. just trying to get the facts straight for myself and anyone who searches for the information later on.

[jbd5015]

the biggest difference would be the transmission lengths that change the length of the driveshaft. Having put 3 different transmissions in wolfie, i can attest that a transmission needs to be mated with the driveshaft it was mated with.

Also, on the M6 ive heard that they have a different diff, a 'large' case diff. perhaps that also changes the driveshaft? Im not an expert on that one though.

-Jeff

[Layne]

Personally I think 6mm is not an acceptable margin of error when it comes to driveshafts. I've seen people do worse things though.

Any E24 or E28 transmission will fit in any E24 or E28 (excluding E28s with smaller engines) with the proper driveshaft and shifter. But putting the 280 in a 635 would serve no purpose except to double the cost of your transmission. Plenty of people have put 265's in the M cars and I don't know anyone that's unhappy with it. Personally I'd rather just stick with a 280 though.

[alpinacsi]

Just some random thoughts on the subject.

BMW drive shafts have a slip joint where the sections meet. You might be able to "stretch" the shaft but that does not mean you can make it shorter.

Do not know the interchangability here but some of the earlier cars used a thicker guibo that might make up for a shorter shaft. (again, do not know about compatability)

You can change from med case to large case diffs without changing shaft.

The 280 trans has the gear ratios matched to keep the M engines operating in the proper power band. This can create a performance advantage when coupled to the proper final drive and engine power band. This does not mean you can couple this to a b34 or b35 and expect any gains.

[e24mpwr]

When I was talking to Metric Mechanic about buying their 280-->265 swap tranny, they said you could have your driveshaft lengthened to match the 280. In the end, I went with a new factory tranny.

I'm familiar with the seller and have known him to be a very straight guy. That said, a 100K-mile 280 isn't something I'd have huge confidence in unless it was a Blanton rebuild.

On the other hand Layne - for the Buy-It-Now price, I could probably see you rolling the dice. Shoot - the core fee for a 280 is $350.

For non-M-cars, I think the ratios would be a disadvantage. :dunno

[Layne]

I need to add 152mm to the driveshaft for my 740 manual conversion. Wonder if I can just put 5 guibos on instead?







:D

[Seeker]

Just some random thoughts on the subject.

BMW drive shafts have a slip joint where the sections meet. You might be able to "stretch" the shaft but that does not mean you can make it shorter.

Do not know the interchangability here but some of the earlier cars used a thicker guibo that might make up for a shorter shaft. (again, do not know about compatability)

You can change from med case to large case diffs without changing shaft.

The 280 trans has the gear ratios matched to keep the M engines operating in the proper power band. This can create a performance advantage when coupled to the proper final drive and engine power band. This does not mean you can couple this to a b34 or b35 and expect any gains.



it's that slip joint that I figured could go IN by about 6mm.. thats like 1/4".. right? I figured it would at least have that much adjustment/play in it.
I agree that stretching by 1/4" would be more of a sure thing and actually allow a '85 or G265 intended 635 DS to work with a 280 w/out issue.. its going IN that may cause more issue to worry over.. according to the e28 m5 dude I referred to.. the 265 is 6mm LONGER.. so the M5/M6 DS would have to be shortened. Right?



I would think $$$ is best spent on a higher ratio diff. for a NA'd M30 than to waste it on a 280 mated to a NA'd M30. Thats my experience with my e36 anyway..


I think this is good discussion considering the fail to cost ratio of 280's vs. the use of a 265 on a ///M.
There may come a day, that may already be here, when using a 280 again on a ///M would be stepping way backwards to keep the ///M alive. Think about all the M6's we've seen that have lost their M88/S38's... they have potential to be restored with a M88/S38 later on.

Having alternative choices with concrete information is crucial IMO.

[Layne]

It's been a while since I looked, are the diff mounting holes slotted on these cars? I assumed the M5 owner had just slid the diff back. If he didn't make a concession somewhere, the extra length is eventually going to damage the trans, diff, or both.

If you look on Scottie Sharp's forum, somewhere there rebuilt his 280 for a few hundred bucks. I don't think they're obsolete yet.

[alpinacsi]

The subframe bolts for the large case diff are in the same relation to the pinion flange as the med case diff. The pinion flange to diff mount is the same on both diffs. The pinion flange to output shaft dimension is different between the 2 diffs. This apprently did not create an issue as that is the way that BMW laid out the system.

If you have to slot or elongate the holes to mount any diff, then you are not doing it properly. All bolts should be started before any are tightened. Start the top bolts first.

[Layne]

If you have to slot or elongate the holes to mount any diff, then you are not doing it properly.

E21's have long slots in the subframe where the diff mounts, I was just asking if E24/28 had the same (apparently not).

[alpinacsi]

E21's have long slots in the subframe where the diff mounts, I was just asking if E24/28 had the same (apparently not).

Sorry, I have just heard of too many people slotting the e24/e28 to make the diffs bolt up. I was speaking specifically of the e24/e28 as it has been close to 25 years since I wrenched on an e21.