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5 speed upgrade


Guest Anonymous
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Guest Anonymous

I'm working on a 5 speed upgrade and I bought a 5 speed overdrive on craigslist and brought it home. I also picked up most of the modified linkage bits except for the rod that goes from the transmission linkage output shaft to the shift lever. I just brought home the rod that I've shortened and welded. I put it all together and the transmission seems to be stuck in first gear. Is there something I can do or should I just call up the guy I bought the transmission from and try to get my money back.

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what usually happens is they get dropped on one end or the other and the weight of the 1st/2nd slider pulls it into gear. Try standing it on the output shaft end on a piece of wood (usually a 4X4 block) MAKE SURE YOU DON'T HIT THE END OF THE SHIFT SHAFT. Thump the gearbox on the block lightly and see if it comes out of gear, you might have to try a number times each time a bit harder. If that does not work do the same thing thumping it on the input shaft end (the question is if it is stuck in 1st or 2nd gear)

We had this happen at the dealership with a factory replacement gearbox in '82 the first time.

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Guest Anonymous

Just a quick note; After looking it over again it's not stuck in first gear as the shift lever is back, and as I turn the input shaft the output shaft is turning at about a 1 to 1 ratio. I think that might put it in 4th?

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Guest Anonymous

Thanks I'll give that a try.

Just a quick note; After looking it over again it's not stuck in first gear as the shift lever is back, and as I turn the input shaft the output shaft is turning at about a 1 to 1 ratio. I think that might put it in 4th? Not sure.

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it is possible the same thing could happen in 4th gear. But it is possible someone had it apart and the 4th gear syncro is jammed on the gear. Can you select any gears with the shift lever? if you can move the shift shaft in or out it is not stuck in a gear. If any of the internal shift rods have moved enough to engage a gear then the other will be locked in in the neutral position. If the syncro is stuck on the gear the shift fork will move.

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Guest Anonymous

I've tried hitting the body of the transmission with a leather mallet in the vertical position with no luck (tried it with either end up). The shift shaft will not move. 'm thinking I might have to try and get my money back.

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Before you do that, take the big plug by the shifter off and try again.

(it's on the extension housing, up high, I think maybe to the left... or right...)

It's a detent (I forget which one) but it can get misaligned and jam things up.

Careful- I think it tries to launch itself into the next county over...

hth,

t

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if the shift shaft will not move it is stuck in gear. you need some inertia to get the fork and collar to move (this is how it moved in the first place) I wish people would ship these things in gear and this would not happen.

The reason the shifter will not move is because the springs center the linkage in the 3-4 gate and if either the 1-2 or 5 shift forks move it does 2 things, it locks the other shift shafts so they can't move (designed to keep you from getting 2 gears at once) and it also misaligns the slot through the shafts that all line up when they are all in neutral. It is most likely in 1st or 2nd gear but the shifter is in the gate for 3-4 and that shaft is locked because the 1-2 shaft has moved from the neutral position.

You need to "drop" the gearbox on one end or the other (do it on some wood so you don't mess up the shafts) just turning it on end and smacking the case with a dead blow hammer is not going to do anything.

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Guest Anonymous

Thanks for he help. I've tried this a couple of times with no luck yet. I'll take the transmission to work with me (200 miles from home) and try there over the week. IF I can't get it to unlock should I try opening it up or would that just be opening a can of worms? I've rebuilt motorcycle transmissions before and been inside the transmission on my spitfire, but this one looks a bit more intimidating.

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You can take the bellhousing off and access things easy enough. The only problem will be getting the input shaft bearing off, There is a special puller that makes this very easy, and putting it back in is even harder because you have to hold the input shaft OUT while you press the bearing over it and into the case (again special BMW tool makes this a breeze). If you know someone that has had a BMW gearbox apart before and is willing to help it would be worth the effort. It might be time to send it back to where you got it.

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how do you get one out of reverse...the trans in my e21 got stuck in reverse and i ended up swapping trans but still have the one that i removed, that's still in reverse

Is this a 4 speed or OD 5 speed?

Once again see below pulling the box apart is not that hard if you have a couple of special tools.

I don't think I have ever run into one stuck in Reverse. Not sure what would have caused this. The only thing I can think of is if the box had been rebuilt and they forgot to put in the ball for the interlock between the 1-2 shaft and the reverse shaft. You could accidently get 1st and reverse at the same time and when you put the shifter in neutral it could leave the reverse gear engaged. I saw this happen a few times with the old 2002 boxes a long time ago (back in the mid 70's)

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