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Discussion Starter #1
My transmission works fine in day-to-day driving, but it sometimes grinds in high-rpm shifts to 2nd... I've been pondering getting a Getrag 265 and fitting it to my car, or sending it to a shop to rebuild the Getrag 280 (they told me it'd cost $2k).

Has anyone had experience with a 265, and is it appreciably better? I hear it's a rugged transmission, but then again it's nice to keep the original 280.
 

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I would swap it out. Not only is $2k too much money to spend when you can install a good used unit, but I don't see the value in keeping it original if the original is prone to failure.
 

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The 280 isn't known for having the greatest shifting syncros. I wouldn't push it. Keep the shifts a little slower and enjoy the trans while you can.They are pretty hard to rebuild if you can even find someone to go into it. I got BK05836 with shot syncros and had to wait quite a while to find a gearbox(280) for it, all the while running an old 535i(260) box. Runs fine but the ratios are a little off in the first three gears. The 265 is said to be a way stronger box but you need to find one with the right ratios or live with the closer gearing. You could always try the Metric Mechanics ultimate 265 conversion with the right gearing for around $5K.BMW Transmissions | Rebuilt BMW Transmission | Metric Mechanic | metricmechanic.com. Pricy. I'm going to keep running my 260 till it sounds like it's going to go,then throw the 280 in. Waiting on the seals as we speak. good luck. Would like to know who can rebuild the 280 or if the parts are still around for them.
 

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Are you using a synthetic gear lube? Specifically not recommended by BMW in the OFS manual.
If so switch back to Dextron II and the grinds will most likely go away!!

Been There Done That!!
Other have tried it and it worked for them also.....

The 280 is the input torque rating for the gear box, so the 265 is weaker.
 

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I'm facing a similar decision.
My gearbag shifts beautifully but 1st-3rd sound like they're straight cut and there's a heap of bearing noise.

For $2k I'd stay with what you know and rebuild the 280, assuming of course you trust the shop and they can actually do it for that price.

To put that into perspective, someone I know recently paid $8k Australian to rebuild their 280 due to worn synchros.
The car then sold for circa $13k.
Just for laughs, I also priced an exchange unit from the dealer at AUD$12k.
 

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Discussion Starter #7
The 280 isn't known for having the greatest shifting syncros. I wouldn't push it. Keep the shifts a little slower and enjoy the trans while you can.They are pretty hard to rebuild if you can even find someone to go into it. I got BK05836 with shot syncros and had to wait quite a while to find a gearbox(280) for it, all the while running an old 535i(260) box. Runs fine but the ratios are a little off in the first three gears. The 265 is said to be a way stronger box but you need to find one with the right ratios or live with the closer gearing. You could always try the Metric Mechanics ultimate 265 conversion with the right gearing for around $5K.
Did it require a lot of modifications (and $$$) to fit the 260? I can source a 265 for cheap, my main concern is getting it to fit right. I heard mixed reviews about the Metric Mechanic trannies, after Jim Blanton left.

Are you using a synthetic gear lube? Specifically not recommended by BMW in the OFS manual.
If so switch back to Dextron II and the grinds will most likely go away!!

Been There Done That!!
Other have tried it and it worked for them also.....

The 280 is the input torque rating for the gear box, so the 265 is weaker.
Using Redline Synthetic, which works really well--made the transmission a lot quieter and smoother. Just can't aggressively shift into second.

The weakness of the 280 synchros is more a function of the brass vs moly-coated rings, so I've heard.
 

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...

Using Redline Synthetic, which works really well--made the transmission a lot quieter and smoother. Just can't aggressively shift into second.

The weakness of the 280 synchros is more a function of the brass vs moly-coated rings, so I've heard.
Change back to non-synthetic Dextron II and in a few K miles the synchros will do better!!
It is worth a try!! Much cheaper than a gear box!!
The notchy feel will subside almost immediately but for the gear grinds, the 1-2k mi. wait is for the synchros to wear back-in also better to chance the Dextron a second time to get more of the synthetic out.
Search this form for others with your problem..
Also, there was a Jim Blanton(sp) Performance Gearing, that rebuilt with new synchros in the 280 and upgrade the trans for synthetic MTL.

Mine is original trans and had some notchy feel and an occasional gear grind up and down in 2nd. Maybe an occasional 3rd up shift.
Totally gone with Dextron II, but a little noisier; I assume as is normal since quite doesn't allow it shift normally.
Owned car since new now 87K miles.. no more notchy shifts or gear grinds at/near redline shifts up or down.
 

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The 260 wasn't a big deal to put in. you will need the driveshaft that comes with it. The 260 trans is shorter in length so you need half of the 535i shaft combined with the M5 shaft. No welding involved. It's a weaker gearbox so it needs to be driven that way, at least they're easy to find and a good alternate till one can get a proper box. I'm able to enjoy the $3000 M5 I found.
 

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Where would one even source the parts to begin rebuilding the trans? Mine does the same thing, grinds in heavy shifts in high rpms up and down shifting in second gear, and the occasional small grind up shifting into 3rd

It's gotten much worse over the course of the year I've had it, but I'm not sure I'd be able to source a good used unit. My car has almost 300k miles, but it seems a lot of other people are having problems with their trans a lot sooner than I did.


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Discussion Starter #11
Change back to non-synthetic Dextron II and in a few K miles the synchros will do better!!
\\
Owned car since new now 87K miles.. no more notchy shifts or gear grinds at/near redline shifts up or down.
My transmission has almost 200k miles on it, so it's a lot older. Redline ATF/MTF 50/50 mix is a popular option, and doing a lot of digging it seems like a lot of people are happy with the setup. I suppose I could try Dextron II, but synchros grind 100% of the time into second when downshifting from 3rd at high RPM... it never grinds in daily driving but I'm thinking it's just old and tired.

Where would one even source the parts to begin rebuilding the trans? Mine does the same thing, grinds in heavy shifts in high rpms up and down shifting in second gear, and the occasional small grind up shifting into 3rd

It's gotten much worse over the course of the year I've had it, but I'm not sure I'd be able to source a good used unit. My car has almost 300k miles, but it seems a lot of other people are having problems with their trans a lot sooner than I did.
Was talking to Pete's gearshop in Northern California, who said he could source the parts from Germany.
 

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Where would one even source the parts to begin rebuilding the trans? Mine does the same thing, grinds in heavy shifts in high rpms up and down shifting in second gear, and the occasional small grind up shifting into 3rd

It's gotten much worse over the course of the year I've had it, but I'm not sure I'd be able to source a good used unit. My car has almost 300k miles, but it seems a lot of other people are having problems with their trans a lot sooner than I did.


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Synchro test!!
With the engine idling and clutch engaged (pedal up).
Push the shifter with a good amount of pressure into each gear and if the gear doesn't grind the synchro cone clutch are not warn out.

The slider and gear teeth may be warn but the cone clutch synchro is still usable however that doesn't mean the gear shift can't beat the syncho if the lube coefficient is to slippery. Also the wrong gear lube will allow the synchro cone clutch to become polished, loss of gear braking and that will cause gear clashes (beating the synchro). In the M5/280 trans if the OE fluid is Dextron II changing back to Dextron will help the synchros reseat, brake the gear better, however most of the time it takes driving mileage for the improvement to show and a second gear lube change with Dextron II helps flush out the synthetic lube that can be causing synchro cone clutch issues.

If the test caused gears grinding it is new synchro time.
 

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Interesting test. I will have to try that and also the fluid change. I have Redline MTL in mine and it does not grind, but the shifts into second are very notchy.

Again, I am going to support switching to the G260 from the 535i. They are cheaper, more plentiful, and lighter. I had one in my old 535i and loved it.

All of these transmissions have shown to be able to handle much more torque than our N/A S38s put out, so I would not have any reservations switching to one of the others.

Here is another argument for making the change. Some chatter from the E34 section of bf.c:

Me:

It has been proven that the medium case rear ends can handle much more power than the M5 and 540i put down. There are also many more ratio options available for less money with the medium case rear ends. This leaves me wondering how much of a difference there is in weight between the two. Even if the sub-frames are the same, the half axles are at least a little different and the large case differential must have at least ten pounds on the medium case.

Pros:

1) More diff ratios to chose from.
2) Medium case diffs are cheaper and more common.
3) A few pounds weight saved.
4) Less mass for the drive train to spin. Between the half axles and larger gears in the diff it might only be a pound or two, but if physics apply here the same way they do with light weight flywheels, it should be considered.

Cons:

1) Labor

Does anyone have any data they could share? I have a large case half axle I can weight.

If dropping a subframe on a M5 or 540i for whatever reason, might it make sense to swap to a medium case setup while you are at it?


TheStigg:

E34 medium case = approx. 82 lb. E32 750 large case = approx. 106 lb. (bathroom scale accuracy). As mentioned, there are dimensional issues to swap them. At a minimum, the rear driveshaft would have to be lengthened to mate a medium case into a large case chassis. The input flange and axle flanges cannot swap large to medium or visa-versa, but if the driveshaft cv joint has the same hole pattern, it will mate large or medium. Also, if the cv axles are the same hole pattern, they will mate large or medium.

Here are some measurements I made a few years ago comparing the 2:

http://www.bimmerforums.com/forum/sh...case-diff-swap


Me again:

Now I am considering also the weight difference between the G280 and the G260/6 from the 535i. The G280 is expensive, loud and clunky. If I could throw a G260/6 and everything that goes behind it, it might make for a good way to spend a weekend. Lighter car, less rotating mass, quieter gearbox, and more gear ratios to play around with.

wanganstyle:

~20 lbs between g260 and g280

20 lbs between 188mm lsd and 210mm.

Should bolt in to a s38 car with the g260-6+driveshaft and 188mm diff.

The addition data not considered is the weight of the ring gear and lsd unit; they turn.

The 188mm ring gear will be 30% lighter (depending on ratio some i.e. 3.15 and 3.91 are lighter than others)

Output stubs from the 210mm unit are also much thicker and heavier; the flanges however are the same 96mm cv pattern.

A 210mm ZF lsd is roughly 25 lbs of rotating item; a 188mm ZF lsd is about 17lbs.

Going to a 188 rear end will be = similar to shaving 12+ lbs off your flywheel; some one with an advanced engineering degree can calculate the exact specifics

results = similar to some very light wheels or a lightweight clutch/flywheel set.

M5 cv axles can be retained; the 188mm differential output stub shafts from a 535i manual or e36m share the same 96mm bolt pattern.

Putting 3 discs In 210mm lsd is pretty silly; unless the goal is drag racing or tuning the car to understeer more. A real drag car will need a 4 disc unit; 3 is uneven loading on the differential- and yes I have built both 188/210 down the 1320 @1krwhp-1.2krwhp for a local clients drag car (160++ traps)

The oem 210mm lsd configuration is designed by bmw to take a m5 e39 5000cc s62b50 engine; If worn out just replace the parts needed.


I am on the hunt for a 535i/5 parts car to swap over the rear half of the drivetrain. I have a G280 that shifts very well with less than 90k on it but I would rather go for the 260 than use it.

----

Here are the ratios for the G280 and the G260:

G260: 1=3.83 2=2.20 3=1.40 4=1.00 5=0.81
G280: 1=3.53 2=2.08 3=1.35 4=1.00 5=0.81

You can see that you will run through 1st-3rd gears a bit quicker, but that 4th and 5th will be the same. Some might want this. I would rather take that, swap in a shorter diff ratio since there are so many options with the medium case diffs, and end up with nearly the same first three gears but gain an even shorter overdrive ratio for highway cruising. For example, swap out my large case 3.91 diff for all of the medium case running gear and a 3.64 diff.

Bolt on, weight saved, more options, cheaper, more plentiful.
 

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Discussion Starter #14
I think there's little reason to swap a 260 over the 265. The 265 is also plentiful, cheap, but is known to be a rugged transmission. The Getrag 260 synchros aren't known to be that strong.
 

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When I put the 260 in my M5 I kept the M5 dif. and used the back 1/2 of the drive shaft from M5 so there was no dif. problems ie. smaller flange. Everything else pretty much fits, gotta move the center bearing to one of the other mount holes and same for the rear mount. Easy enough to do. I just got a hold of a 265 so now I've got the three options. The 265 looks like it needs a different bell housing tho.Also there is some fancy fab work to do to get the shifter to work. New seals are in the 280 so that will probably go in next. I'm in no rush since the 260 runs fine. Aloha from Maui
 

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Discussion Starter #16
When I put the 260 in my M5 I kept the M5 dif. and used the back 1/2 of the drive shaft from M5 so there was no dif. problems ie. smaller flange. Everything else pretty much fits, gotta move the center bearing to one of the other mount holes and same for the rear mount. Easy enough to do. I just got a hold of a 265 so now I've got the three options. The 265 looks like it needs a different bell housing tho.Also there is some fancy fab work to do to get the shifter to work. New seals are in the 280 so that will probably go in next. I'm in no rush since the 260 runs fine. Aloha from Maui
It's a removable bellhousing, as long as you get the one for the bigger six-cylinders (M30 as opposed to the smaller M20) it should mount up fine.
 

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I thought I'd resurrect this thread. I just swapped in a 260/6 from a E34 535i. I have a 260/5 in my modified E28 which has more torque than the M5, and I have never had a issue with that transmission with high torque, so I oped not to go for the more expensive 265.

Everything bolted up nicely, using the front half of the E34 driveshaft coupled to the rear half of the M5. As noted in a post above, the 260 has slightly higher gears in 1st - 3rd and the same 4 &5th gears as the 280. I think this is an advantage and helps compensate for the lack of low end torque around town. I also added a Autosolutions shift kit which is perfect!

baviarnstig just posted a video of him running through the gears a bit (although you can't see his speed). I thought I would post a video of the same thing with mine and the 260 transmission for comparison.

Stigs w/280: https://www.youtube.com/watch?v=QE5GfUxzSoU&feature=youtu.be

My 91 w/260: https://youtu.be/3gN03DKK06o
 

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Nice one.
Looks like Stig's getting about 100km/h at 7k in 2nd whereas you're getting mid 90's, which is spot on with the 2.2 vs 2.08 ratio.
I've been running a 260 for a year now and can't really notice any difference, although I rarely visit 7k RPM.
 

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Nice one.
Looks like Stig's getting about 100km/h at 7k in 2nd whereas you're getting mid 90's, which is spot on with the 2.2 vs 2.08 ratio.
I've been running a 260 for a year now and can't really notice any difference, although I rarely visit 7k RPM.
Agree. I've read several posts where guys say the 'gearing is a little off' as if there is a noticeable difference or downside. As you point out, it's negligible between the two transmissions. That's why I posted the video, to give a visual as I think this conversion will only become more popular.

I didn't intend to hit 7K! :eek:oohhh::M5rev::M5rev: I didn't expect it to climb that quickly in 2nd. Being able to wind out 2nd is new to me.
 

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The 260 actually has lower gear ratios in the first three gears. But you're right in that it's not that big an issue, especially if it gets the car going again while you can source up a 280. I'm happy with the 260. I don't abuse it and shift nice and easy. I don't have any freeways here so like I mentioned in other posts, I don't mind the lower gears. Some day the 280 will go back into mine, and yes I'll be running atf. Aloha
 
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