How hard is it to rebuild a manual transmission?

Kinja'd!!! "Anon" (tjsielsistneb)
05/13/2014 at 23:07 • Filed to: None

Kinja'd!!!0 Kinja'd!!! 16

I like to think that I'm mechanically inclined however I've never done any work with transmissions before. Do you think I could rebuild one without having anyone who's done it before? Do I need any special tools for the job?


DISCUSSION (16)


Kinja'd!!! Satoshi "Zipang" Katsura > Anon
05/13/2014 at 23:10

Kinja'd!!!0

It kind of depends on the transmission in question.


Kinja'd!!! Zipppy, Mazdurp builder, Probeski owner and former ricerboy > Anon
05/13/2014 at 23:11

Kinja'd!!!0

It's cheaper to replace the transmission than to rebuild it, as the individual parts tend to be more expensive. The gearset replacement itself is typically more expensive than the transmission. I took one apart using tools out of the toolbox at school, and the synchronizers are very tricky to replace.


Kinja'd!!! Opposite Locksmith > Anon
05/13/2014 at 23:12

Kinja'd!!!0

really depends on the transmission. But find a step by step guide. They exist.

My Subaru 5mt will need it soon. 420 lbs ft have not been kind


Kinja'd!!! Racescort666 > Anon
05/13/2014 at 23:13

Kinja'd!!!0

special tools depend on the transmission but it's really not that hard. Honestly, if you can take something apart and put it back together, you'll be fine. Make sure you check up on the forums of whatever vehicle it is and, if you can, get a hold of the factory service manual. That will give you the best idea of what you're in for.


Kinja'd!!! Anon > Opposite Locksmith
05/13/2014 at 23:13

Kinja'd!!!0

It's a midlands 5 speed


Kinja'd!!! ZiptieMcBumper > Anon
05/13/2014 at 23:21

Kinja'd!!!0

I wouldn't do your first job on a transmission that you're going to need quickly. It is a do-able job if you've done moderately difficult mechanical repairs before.

Assuming you're just doing a normal overhaul, (gaskets, synchros, bearings, etc.) and you have a well-stocked tool chest, there aren't really any special tools you need other than snap-ring pliers. Access to air tools is a big help when removing the transmission and disassembling it.

To reiterate my first point, you shouldn't be afraid of the job, but if you have the means to do so, start by disassembling a spare transmission first to make sure you're comfortable with the job. Don't forget proper assembly lube; make sure you use the right stuff.

Oh, and get your hands on a service manual if you don't already have one.


Kinja'd!!! Anon > ZiptieMcBumper
05/13/2014 at 23:26

Kinja'd!!!1

Between my dad and my grandpa I have access to more normal tools than you could believe, it's the specialty stuff that's the issue. I don't start summer classes for 3 weeks so if I do it in this time I should be fine.


Kinja'd!!! ZiptieMcBumper > Anon
05/13/2014 at 23:35

Kinja'd!!!0

Sounds like the perfect time to give it a try! I just mentioned the snap-rings since most people don't seem to have them. Even if you don't, a good pair will only run you $15-20 US.

Depending on the age of your vehicle (I'm assuming at least 10 yrs old, if you have a mini), air tools are a big plus.


Kinja'd!!! DipodomysDeserti > Opposite Locksmith
05/13/2014 at 23:35

Kinja'd!!!0

Damn, 420 lb-ft on a Subie 5mt! What are there 1k miles on it?


Kinja'd!!! Anon > ZiptieMcBumper
05/13/2014 at 23:40

Kinja'd!!!0

Close, 8, she's a 2006 BMW Mini. I can probably borrow air tools from someone though.


Kinja'd!!! ZiptieMcBumper > Anon
05/13/2014 at 23:46

Kinja'd!!!0

Good luck!


Kinja'd!!! Levitas > Anon
05/13/2014 at 23:49

Kinja'd!!!0

Well I just saw that its a Midlands 5spd. I thought about rebuilding since I had access to a full shop with presses, mills, lathes, etc., but I decided against it. I ended up picking a new one up from WayMotorWorks, but unfortunately, after 12k miles, a brand new tranny is going bad once again.

Somewhere, I have a PDF of the entire tear down and rebuild of the Midlands from Rover group. I'll see if I can find that...


Kinja'd!!! Opposite Locksmith > DipodomysDeserti
05/13/2014 at 23:55

Kinja'd!!!0

just had my 60k mile service biiiiiiitch (sorry)

15k since my "build"


Kinja'd!!! YSI-what can brown do for you > Anon
05/14/2014 at 00:05

Kinja'd!!!0

This is a perfect time to buy a sequential straight cut gearbox.


Kinja'd!!! Squid > Anon
05/14/2014 at 01:54

Kinja'd!!!0

Get the FSM for your car! That isn't just a suggestion. It should have the removal and teardown/assembly instructions for you to follow. Rebuilding a tranny isn't a terrible job, but requires patience and time and the ability to set your fasteners to the PROPER TORQUE. Get the FSM and read the procedure a few times all the way through, from removal of the tranny from the car to the full teardown and assembly. You'll find out if you need any special tools when you look up the procedure in the FSM. If you do decide to do this and you are dropping the tranny down while the car is on jack stands, be prepared to have it sitting on stands for a minimum of a few days plus how ever long you have to wait for parts if you have chewed up gears. You will need an engine support that will hang the engine by using the fenders as support since the tranny will no longer be there to support it.

The main thing is to read through the procedure so you have an idea of how big the job is and so you don't fuck shit up in the process of trying to fix something. Get as educated as you can on dropping and cracking that tranny apart before you remove a single bolt and you should be fine. Just remember to use lube and torque everything to spec.


Kinja'd!!! DipodomysDeserti > Opposite Locksmith
05/14/2014 at 08:15

Kinja'd!!!0

Nice. Did you swap the fluids out for any of the cocktails? My WRX had 50k on it when I bought it and the synchros were starting to go. I put in a 3:1 mixture of redline shockproof and motul gear oil and it got rid of the zip grind.