Getrag 235 rebuilt!

[dscoff]

Haven't had much time for '02 project this winter, but if I had to choose one, it was rebuilding my 235 close ratio dog leg gear box. It weeped (read: leaked) from the speedo gear and the rear seal, I clenched my teeth with every ginger shift into 2nd and it just felt generally sloppy and tired. Having researched the rebuild online, it sounded like parts availability was going to be an issue. Not so! Maximillion Importing was able to provide all the parts I needed including 1st, 2nd and 3rd synchros, all gaskets and seals and a few odds and ends like the mini-freeze-plugs used to remove the interlock and detent balls.

I finished reassembly on Thursday and with two days of driving done, the difference is remarkable. The box is crisp and very notchy with super positive engagement.

[c.d.iesel]

good on ya mate!

a very satisfying job indeed.

sometimes you find wear on the sides

of the shift-forks from hamfisted nutt's

behind the wheel - who kept their

paw pushing on the shifter - especially

if it was popping out of gear.

Sounds like you had patience, lots of parts,

no rush to do it right, and no cost limits.

Most people faint when they add up the parts

cost and time involved.

[dscoff]

The cost (in terms of car expenditures) wasn't too bad: about $360 in parts and a couple of days labour. I didn't replace 4th and 5th synchros mainly because they're weren't too worn, but also because they were $130 each.

[Cameron]

The cost (in terms of car expenditures) wasn't too bad: about $360 in parts and a couple of days labour. I didn't replace 4th and 5th synchros mainly because they're weren't too worn, but also because they were $130 each.

$360 sure is cheaper than finding another dogbox! nice work

[Beaner7102]

Could you post the part list you bought?

I have been thinking of doing a simmilar job on my 5spd, but dont know which parts I actually 'need' and others that can stay as is.

Cheers Beaner7102

[im3crazy]

+1 on the parts list for general rebuild and most commonly needed to replace.

Cdiesel and blunt may have these. Also the getrag rebuild manual is on here.

[dscoff]

No problem. I'd say wait until you've pulled the box apart to before ordering anything. There's always the chance of surprises in there or that you'll break something during disassembly. Here's what I ended up ordering:

23111606108-Sealing cover

07119965060-Shaft seal

23121222356-Gasket (X2)

07119937220-Cover lid (X4)

23121205522-Ball bearing

23121204209-Shaft seal

23121222355-Gasket

23231200777-Synchro ring (X3)

23121490177-O-ring

25111208580-Supporting bracket

23121200730-Gasket

07119963130-Washer

You may not need 4 "cover lids" (they're the mini freeze plugs used to remove and replace detent and interlock balls); I disassembled the box without the Haynes manual, but when reassembling (with the manual) realized I probably only needed to pull one or two of them.

I didn't need any super special tools (like the bearing puller for the 4-speed), but you'll need a thin walled 30mm socket to remove the output flange nut and a pin tool (easily made) to hold the flange. The bushing that the reverse gear's bearings ride on was fairly tight, but nothing a little heat didn't help.

My only other tips would be to firstly make measurements and diagrams like crazy: I measured every shim, c-clip and other part and carefully drew it's placement and orientation. It may seem like overkill, but 1) you can then easily clean all the parts without worrying about mixing them up and 2) when you're in the depths of reassembly is a crappy time to find a spacer with a chamfer who's direction you can't remember. Secondly when putting the forks, rails, selector rod and detent/interlock balls back in place, leave the roll pins just barley in place until you've tested that the selector dog engages each rail and nothing interferes. It's a bit of a chinese puzzle and if you drive the roll pins home only to find you need to back up a step, everything has to come apart to get them out.

Have fun!

EDIT: I realized the first photo I posted shows the rails/forks/selectors in place with the pins just barely in.

[MrSharky]

that's awesome!! I love seeing pictures of the car's "innards".

Great job on the rebuild too!!

Matt

[bueller]

very awesome. are there any animations that have how the innards actually work? i've seen such but only with engines, not transmissions. would be cool.

matt

[dscoff]

I have an automotive text book called "Automotive Technology: A Systems Approach" by Jack Erjavec, which has a good explanation of manual transmissions and good diagrams including the power flow. This refers to the actual "path" that the power from the input shaft takes to the output shaft in a given gear. Most of the components in a trans are moving at all times, but that doesn't mean they're all transferring power. If you can understand how the power flows and thus how the gears work, it makes understanding how syncros work much easier. That said, there are a few different styles of syncros that work slightly differently but the concept is the same. Unless you're a very visual learner, the only way to pick up the details is to look at one partly disassembled, although with the price of tired 4-speeds at $50-70, it would be a cheap investment to learn on.

[TobyB]

Yeah,

the best- shifting 2002 box I've ever used was one that David Lumbra rebuilt

for the PO of my race car.

There's really nothing wrong with a nice, freshened 2002 box.

t

[Vetle]

Hi!

Iam now trying to disassemble my 235. After you removed the the flange, the bolts and the segi ring in the front, what do you use to split the gear box?

[TobyB]

The special tool that pushes the input shaft out of the front case...

 

t

 

[Preyupy]

There are a number of special tools that make the process much easier.  A puller that removes the input shaft bearing and another one for the output shaft bearing. There is another tool that presses the input shaft bearing back into the case while pulling the input shaft OUT so you don't drive the input shaft down over the 5th gear synchro and have trouble putting the snap ring back on the shaft.