DIY Manual trans Rebuild

[paulsomlo]

Below is a photo of a new clutch fork pivot pin. I don't have photos of the old one, but as I removed the transmission from the vehicle, the old pin came tumbling out - the broken portion, that is. The pin had snapped at some point, where the stem was pressed into the case. The pin also showed signs of severe melting at it's tip. I turned a new one out of mild steel to replace it. I would not replace this part with the OEM plastic one, but would recommend one of the bronze or steel aftermarket ones. I didn't have a transmission jack, so I made a wooden platform for my floor jack, which worked very well.

In retrospect:

My 1st gear problems were completely clutch related. I replaced the pressure plate, disc, throwout bearing, pilot bearing and pivot pin, which made shifting into 1st from a standstill much easier. I ended up replacing the 1st and 2nd gear synchronizer rings, which I believe may have been unnecessary, and expensive. I replaced the three seals, as well as the two mainshaft bearings. If you're wondering why I didn't replace all the sync rings, look up the prices on RealOem. Sync rings for this box average $90 each, one bearing was $62, the other, $72. The bearings are "specials", made for Getrag. I tried bearing houses both local and national, and no one could source them. Parts were purchased from Bavauto.

Normally a rebuild would entail replacing all five sync rings. In this case, all the sync rings, bearings and seals come to over $700. This is why you don't see much rebuild info on these boxes on the web. It's just not economically justifiable, in most cases. The two sync rings that I did replace were based on my perception that these would wear the most, and this way, I won't have to deal with them for a very long time. I finished up by filling the case with Redline D4 ATF, which has helped cold weather shifting noticeably.

Thaniel rates closing up the box a "10", as far as level of difficulty, and I would agree. This was an extremely challenging project and wrought with frustration. I spent about $350 in parts, probably unnecessary. But, for my $350, I got quite an education. Admittedly, knowing how difficult this is, I would probably opt for a replacement box in the future. If you choose the rebuild route, come armed with lots of patience (and a shop press).

Paul Somlo
Greeley CO

[NervoS]

Wow, thanks a lot for sharing. I wish someone publishes same info about zf 6 speed tranny.

[paulsomlo]

I did some looking around for info on the 6 speed, because I briefly considered looking for a used one to replace the 5 speed, but couldn't find anything on RealOem, and I'm thinking that parts may not be available, as well. That makes buying a used one a gamble, and new ones are somewhere around $3k, a bit impractical for a car that may only be worth $2500. I sure would like to have a six speed, though, because the 'ti turns around 3000 rpm at 65 mph.

[Morgion]

Thanks for the extremely informative thread. I need to swap the noisy input shaft bearing of my Getrag 250 G sometime sooner or later, this made me think twice about swapping a new trans in there instead. So I only need to remove the bell housing from the rear case and then remove the bearing from the bell housing in order to swap it?

I sure would like to have a six speed, though, because the 'ti turns around 3000 rpm at 65 mph.

Amen, a sixth gear is what E36s desperately need.

[paulsomlo]

Yes, I think Thaniel covered most of it in his post #4. Once you separate the case, you'll need to remove the bearing retainer, then heat the outside of the bearing bore with a heat gun, and the bearing will drop right out. When you reassemble, let the rear case half rest on the output shaft, that way the output bearing is protected and the force of the press is borne axially along the mainshaft. I left out a lot of detail in my posts, so as you get closer, if you have questions, I"ll try to answer them.

[Morgion]

Seems I won't be swapping transmissions after all. Thanks, I just saved $500 thanks to you.

[avangeline]

Now that the trans is apart the problem is very obvious.

[paulsomlo]

Now that the trans is apart the problem is very obvious.

Oh?

[Thaniel]

I wanted to add to this thread, having just gone through a rebuild of the Getrag 250 in my 1996 318ti. The car has 199,000 miles on it, and was exhibiting hard shifting, especially in cold weather.

I'll focus on assembly, since I can't add much regarding the disassembly process.

thanks for adding your info and knowledge.

[tiger318i]

Thank you so much (both of you) for your write up's. 3 years later this information is still very valuable! I lost 3rd and 4th gear in my 95 325is. I bought the car in June 2011. Both gears would grind/clunk a little before going in so i knew the synchro's were going. 4th would clunk 50% of the time. 3rd would do it all the time. Eventually i would have to touch my nose\operate a window\turn off the ASC+T while pressing in the clutch (basically it would just grind and if i were really lucky it would go in). Then one day (~spring 2012) 3rd wouldn't go in at all, just grinding. Then (dec 2012) 3rd gear just vanished (as in) i can dis-engage or engage the clutch and its as quite as a mouse. Jan 7th 2013, 4th gear disappeared on my way to work. It worked the entire way to work (~40min drive) and when i was 5min from work i went to put it in gear and it was silent, like it was in Neutral. Lets say im driving in 5th gear down a hill and put it in Neutral. Without pressing in the Clutch pedal i can put it in 3rd or 4th and it feels like it would if the Tranz were in Neutral.

So Thanks to your information im going to buy a tranz from an e36 318i and drop it in, then open the bad tranz up (somethings got to be broken inside) and investigate. Im leaning towards a shift rod being broken. i'm pretty sure the shifter & associated assembly is fine, except for the shift arm bushing (OEM Pt #25111222015), which i KNOW is shot. But i highly doubt thats why i dont have 3rd and 4th since 2nd works fine. Open to any ideas or suggestions. tearing into this tomorrow.

[paulsomlo]

The commonality between 3rd and 4th, of course, is that they both use the same shift fork/rod and slider/hub assembly. Worst case scenario, the dog teeth on both 3rd and 4th speed gears have been sheared off. Once this happens, the clutch becomes superfluous. It's also possible that the teeth on the slider are worn as well. While the sync ring (aka "blocking ring") most likely contributed, I think the problem is beyond worn blocking rings. Even with worn rings, you wouldn't get away with shifting with the clutch engaged.

The other possibility, the one you should hope for, but I'm not optimistic, is that the roll pin that holds the shift fork on the rail has sheared, but I just can't see that happening. I'll include a drawing from RealOem with a portion of item "8" circled - this is the part of the 3/4 shift rail that engages the selector rod. If somehow that feature were compromised, you wouldn't be able to move the rail. Another thing to look for, if the dog teeth/slider teeth are compromised, is wear on the shift forks where they contact the slider. Are you planning on reusing the bearings? If so, you'll want to take precautions when disassembling. And if that's the original clutch, you'll want to replace the pressure plate, disc, throwout bearing, pilot bearing, clutch fork, and pivot pin.

I'll be very interested in what you find - if you have access to a small shop press, the dissassembly will be fairly straightforward.

Paul

[paulsomlo]

One thing that might make disassembly a bit easier; there are two dowel pins, used for locating the two case halves, you'll see them when you remove the fasteners that hold the case halves together. Removing those might make separating the case halves easier. One is accessed from outside the case, the other is most easily accessed from within the bell housing, using a long rod.

62 degrees in Pittsburgh today, I envy you. Hope you can take advantage of the weather this weekend to get the gearbox out.

[hakentt]

Do to the introduction of heavier E46 323i. Getrag 250 was improved and improved version was installed in all April 1998 production models and on. 2nd gear teeth colapse do to design flaw of the mainshaft bearings and bushings. Last two digits of the part number indicates year, like 98 or 99, those are the ones you want.

[tiger318i]

Thanks for the vote of confidence Paulsomlo. The weather on Saturday and Sunday was beautiful indeed. I couldn't ask for a better day in January to work on my car. Everything was going as planned. Ran to the junk-yard to grab a front sway bar for a friends Legacy Wagon, and found one that was already pulled. Made it to the second junl-yard to snag my Tranz right as they were closing. And got it for $100 (told them i needed a 318i manual tranz, they wanted $350 for a 325i tranny and im 99% sure they're the same?)

I do not have power or air tools so it takes me a bit longer than most. but i got the car on 4 jack stands ~2.5ft off the ground (im 5'5" 120lbs), spent 4hours sat setting up and ripping everything out. I got every single bell housing bolt out but when it came to removing the top dead center bolt from the transmission (the one directly to the right of the starter bolts) it wouldn't budge. 1.5ft breaker bar with cheater pipe= snapped 3/8" extension. I then proceeded to try again and then began to strip the head of the bolt. I was using the correct inv-torx socket and everything. Just stripped it. Over and over again. Then used a 6pt and 12pt variations; stripped it some more. Total Time spent...
Sat: 4hours to disassemble, 4hours fighting with the bolt
Sun: Another 4hours fighting with the bolt, 4hours to reassemble
Took it to the garage the following Thursday to see if they could torch the head of the bolt...they deemed it not possible to get to+fear of catching the car on fire (Oh, and while they were working on it they left the drive shaft hang, so now the center drives haft bearing makes a horrible noise. Granted it was 18yrs old, but wtf?) SO now i'm either going to get my hands on a personal blow torch and try it myself...or remove the fuel rail, intake manifold, windshield wiper assembly, and all other crap in the way and try to get the bold from top of the bell housing by the firewall.

"...Are you planning on reusing the bearings? If so, you'll want to take precautions when disassembling. And if that's the original clutch, you'll want to replace the pressure plate, disc, throwout bearing, pilot bearing, clutch fork, and pivot pin..."

Paul

I would love to replace all of these but as of now money is a bit tight, even if it is $50-$100. If possible ill replace the Input and output shaft bearings and seals, and guide bushing. but this car needs so much work done that i can't dump too much into one area. gotta diversify my bonds

[paulsomlo]

Very sorry to hear that. That's the one that seems to give everyone fits. When I did mine, I had the intake manifold off to replace the cooling hoses/connectors, so I accessed the bolt from up top using a 1/2" flex head long handled ratchet, Sears PN44984. I think most of the guys have used 1/2" extensions to get that bolt from down below, because the 3/8" tends to twist. It does tend to be very dry here, and corrosion on fasteners is not a problem.

If you have another vehicle and the weather holds, once you pull the intake manifold, you'll have access to things you never can get to any other way. At 18 years, might make sense to do whatever you can while you're in there. I don't know how the 318i differs, but the only hitch to removing the intake manifold was dealing with the "squid" and the wires that go to the starter.

If the head of the bolt will still accept a socket, you might try running the car for just a bit to warm up the block, maybe get some differential thermal expansion going between the block and the fastener. Other than that, you're correct - you'll need to pull the manifold so that you can see the bolt head.

About that driveshaft center bearing - the Bentley book talks about not letting the driveshaft hang. Make sure that it's the bearing, not one of the universal joints. If it's the bearing, not a big deal - at 18 years, might be time for a change. If the rubber boot is intact, you can change out just the bearing, simple press out/press in. I did that this Summer, the Autohausz PN is W0133-1631859, $21.78.

I sympathize with you; I don't have any air tools either, I did the job this summer using jack stands and a creeper, started 3rd week of August, finished 1st week of November, replacing anything that seemed prone to failure, along the way.

Keep us informed, we're here to help.

[paulsomlo]

Hey tiger - any progress?

[jeffmgr]

Paulsomlo,

You seem to be very knowledgeable about these tranny's so I wanted to ask you some questions regarding my getrag 250. I have a 2002 525i and according to a BMW bulletin, these transmissions had 1st & 2nd gear guide sleeve issues that would cause the 1st gear to pop out.
I have 91k miles and it's starting to pop out again one year after putting some redline MTL in, the redline stopped the popping out of 1st, but only since last March. I was told that I shouldn't rebuild this tranny, but to get a used ZF instead of another potentially bad Getrag. Your thoughts are greatly appreciated.

Jeff

[paulsomlo]

Jeff - I let this slip through the cracks, my apologies.

I downloaded the pertinent tech bulletin - apparently the guide sleeves were incorrectly machined. It doesn't elaborate beyond that, so it's anybody's guess. I have a pdf of the bulletin, be happy to email it to you. I would entertain that the teeth, which are backcut slightly to maintain mesh under torque, are just not engaging fully, either because the teeth were not back cut sufficiently, or some other feature of the sleeve doesn't allow the teeth to engage fully.

The bulletin does imply that the problem was fixed by 1998, though, so it may be normal wear.

The guide sleeve runs around $350, which is about what you might pay for a used Getrag 250. If I had it to do over, I would be tempted to go with a 6 speed as a replacement.

Paul

[paulsomlo]

Had another thought, Jeff - it's possible that the shift fork has worn, as well as the groove on the sleeve in which it sits. Either one would prevent full engagement of the gear teeth of the sleeve and the teeth on the speed gear. That wear, in particular, can be accelerated by resting one's hand on the shift knob. Admittedly, I don't understand the Redline connection.

[Shadowjack1020]

Just found this 9-year-old thread. I see the OP (Thaniel) is still active on here, so maybe it will work out.
Bought a Getrag 250 out of a 2000 Z3 because the trans in my own 99 Z3 has the low-gear synchro out. Before installing it, I found I couldn't get it to shift easily. I believe that problem was caused by jammed shifter detent pins, but I'm way beyond that now. I don't believe it shifts properly even yet, so I need to complete the inspection.
The actual problem: I have already fumbled my way through all the steps to get the front case off, and am now trying to get the gearset out of the rear case. I rigged up a pusher from a 3-jaw puller to press the output shaft out, but it only moves a little bit and then the countershaft seems to be holding it, even though I've unbolted the countershaft bearing retainer. I also can't seem to get the shifter interlock pin out of the hole. Would this keep the rod from sliding out?
I see you used a press to get the gearset out. I do have a press available, but the question is, if nothing else is holding it in, how much force did you use to get it out? I didn't want to mash down on it unless that's just what it's going to take.

[paulsomlo]

Be careful pressing; it's been many years since I've been in the gearbox, but I don't remember anything being difficult to press out. I do remember some retaining clips, but don't have access to my pictures here.

[Shadowjack1020]

Thanks for replying. I've looked intently into the rear case and cannot see anything that could be holding it. It feels like the rear countershaft bearing is very tight in the case bore and is doubling the amount of force necessary to push the assembly out. Maybe. I'll try a heat gun on the case to see if that helps.

[Shadowjack1020]

Well, that was easy. The press didn't even notice the effort. Right up to where I snapped the shifter interlock pin because I didn't notice it was out of line...

[johnny5five55]

im trying to get apart my getrag 250 pulled out front seal snap ring and washer dont see 2nd snap ring any suggestions/pics tnx

[Shadowjack1020]

On mine there was only one snap ring around the input shaft, with a spacer/shim behind it. The shaft is a press-fit into the front bearing, so you have to rig a puller for the case to push the shaft out/case off. Don't forget to take out the front reverse idler gear bolt.