DIY gearbox repair?

[peaktorque]

Hi, I have posted this question on the Alfa forum, but have had no response.

The car in question is a 2007 Alfa Romeo GT Q2 (LSD), which is jumping out of 3rd and 4th gears (it is 6 speed btw) I'm guessing that this is due to worn synchros or selector forks.
Is it worth the hassle to attempt repairing this myself? (I'm an engineer by trade and have rebuilt engines, but never a gearbox) Or is it a specialist only job as I keep being told

I'd rather do the job myself as it will save a few pennies and I learn 'on the job'. One of the benefits of a specialist repair, would be a warranty though...

Any thoughts?

Thanks

[Steve_D]

Most gearboxes require specialist tools to either dismantle or reassemble.
There will likely be preloads or shimming which you will need to find data on.
You would be wise to not try this unless you have a proper service manual available.

Before you dive in do make sure there isn't something silly like a bunched up lump of insulation or torn gaiter around the shift itself. Once doubled the power of a customers car by pulling the carpet out from under the throttle pedal.

Steve

[GavinPearson]

I think the best place to start is by going to the dealer and asking for quotes on the parts you will need and ordering a workshop manual.

Some manufacturers provide exemplary spares support - the dealer may not stock the part but at least you can get it, even if there is a bit of a wait, whereas some manufacturers simply opt for the 'fit a replacement' approach. So the above will determine which way Alfa have gone.

Assuming you can get parts you do need to be aware that you will need access to a press, one gearbox I have a lot of experience with required at least ten tons force to put gears on shafts, and if you get it wrong you will need to spend money fixing your mistakes.

Aside from that it is all pretty straightforward so go for it, I'd say.

[peaktorque]

Thanks for the replies

I have access to a hydraulic press so that side of things should be ok.

As far as the shims go, I would have thought (maybe wrongly) that if I refit them as removed then that'll be sufficient?

I will need a workshop manual though....

I'm going to remove it from the car myself anyway so I'll make the decision once it's out. And I will get a few quotes.


Thanks

[Steve_D]

peaktorque said:

.......As far as the shims go, I would have thought (maybe wrongly) that if I refit them as removed then that'll be sufficient?......

If each gearbox went together the same then there would be no need to design in shims.

If the design has shims (yours may not) then you have to assume you will possibly need to measure and select the required shims.

Steve

[peaktorque]

Steve_D said:

If each gearbox went together the same then there would be no need to design in shims.

Very true.

Thanks again,

James

[spenny_b]

James, I see that you're also in Kent; don't know if you're aware of an outfit called Road & Race Transmissions in Kemsing? Phil Stewart. Thoroughly nice chap, looks after (or did, not spoken to him for a few years) a lot of the Caterham guys boxes and diffs, but also does the more day to day stuff. 01959 524678. Say "Hello" to him from Spencer (he's done a fair bit on my Westfield)

[peaktorque]

spenny_b said:

James, I see that you're also in Kent; don't know if you're aware of an outfit called Road & Race Transmissions in Kemsing? Phil Stewart. Thoroughly nice chap, looks after (or did, not spoken to him for a few years) a lot of the Caterham guys boxes and diffs, but also does the more day to day stuff. 01959 524678. Say "Hello" to him from Spencer (he's done a fair bit on my Westfield)

Thanks, I give him a try.