Replacement gearbox required for GTi

[GRP]

The 2007 Polo GTi gearbox has decided to give grief having done less than 50K. Save for a noise in first gear the gearbox is running fine. Noise in first gear diagnosed as input shaft/first gear issue. Cost of rebuild even assuming only input shaft, bearings, seals and labour easily runs over $2K (Audvolks quote) and then there is the question of what else is found once the box is apart.

Whilst the 2007 Polo GTi is in great nick and under 50K klms, the repair costs looms as a good chunk of the ready sale value. Ultimately the repair costs will rest with my son the uni student which means I will fund it.

Anyone else been down this path?

Anyone have a gearbox or parts?

Do I import a gearbox from the UK or other?

Any and all input appreciated.

Grant

[hardy_bm]

Good time to drop in the Quaife LSD.
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[seangti]

Have you seen a few specialists to diagnose the gearbox? The Polo gearboxes aren't typically a point of failure, I've heard of very few in my ~6yrs on the forum, and typically on cars that have been abused or overpowered. But hey, it'll happen.

Can I assume you've dropped the gearbox oil and replaced it a few times to flush it out and see if that helps?

Importing a box would be rank expensive and our exchange is awful at the moment. A local fix is probably the best bet and most cost effective. I have a felling the mkIV golf GTI gearbox also fits, there may be others. I'm sure a few others on the forum could provide a small list of other cars with interchangeable boxes.

[h100vw]

Golf gti box shares lots of parts but isn't a direct swap. There's a fella up here with a polo he is doing a conversion into a Mk2 golf.
I'll be honest I never heard of a bad input bearing/ shaft on a polo. Not saying it couldn't be.
The release bearings can make awful noises, mine does. I'd definitely be dropping the oil and having a look, change it for synthetic. That clears up lots of syncro related Probs.
If you did swap the box. I'd be interested in the bad one.

[GRP]

I looked at LSD prices whilst I was browsing UK sites

Have not flushed the fuid. I noted early Polo posts about crunchy gears and fluid change fix. The gearbox was silent up until recent times. It now makes a mechanical/chattery/whining noice which is (a) only in first gear and (b) seemingly disappears by around 2500 rpm (or the engine and tyre noises are louder). All gear changes are smooth and clean.

[h100vw]

I looked at LSD prices whilst I was browsing UK sites

Have not flushed the fuid. I noted early Polo posts about crunchy gears and fluid change fix. The gearbox was silent up until recent times. It now makes a mechanical/chattery/whining noice which is (a) only in first gear and (b) seemingly disappears by around 2500 rpm (or the engine and tyre noises are louder). All gear changes are smooth and clean.

Mine whines like a straight cut Mini in 4th. If yours is std power I can tell you the gearbox can handle an extra 100hp with no problems. There's a few on here doing this.

I vote you change the oil for something synthetic and drive it a while.

Don't be pulling that gearbox out just yet.

You'd also be nuts to not change the clutch at the same time, adding to the already mad cost you are looking at.

If you replace the box my interest in the old one remains Cos I have an A3 box I fancy robbing some gears out of.

Gavin

[GRP]

Currently APR tune and front mount intercooler waiting for install.

Couple of votes for oil change. Certainly nothiong to lose and a flush and refill with synthetic is cost effective. Any recommendations on synthetic fill for the gearbox?

[The One]

Do synthetic oil and maybe a diff treatment? Nulon G70 works a treat I've found.

[h100vw]

Currently APR tune and front mount intercooler waiting for install.

Couple of votes for oil change. Certainly nothiong to lose and a flush and refill with synthetic is cost effective. Any recommendations on synthetic fill for the gearbox?

Blatant spruiking but I can save you some money on a tune. I have done lots of Polo's with Phase 1, 2 and 3. For std, cars with downpipes and also turbo changes.

Gavin

[GRP]

Gavin, no spruiking required. The APR tune (bought on special) was a practical thing as I shared the Polo with my son for 12 months whilst looking for a new ride (now in C63 with a tune ). APR offered easy switching between full tune for me and stock for the P plater. You were the first thought for post front mount and down pipe tune. Blatant plug - need cheap down pipe.

[Snail Style]

Not often you hear of an input shaft bearing only making noise in one gear. I'd be trying a fluid change and see how it goes.

[louis19]

Currently APR tune and front mount intercooler waiting for install.

Couple of votes for oil change. Certainly nothiong to lose and a flush and refill with synthetic is cost effective. Any recommendations on synthetic fill for the gearbox?

I'd certainly be doing an oil change before anything else. I had a bad 1st to 2nd crunch, put in Nulon 75-85W Smooth shift oil, had a slight improvement. Then replaced that with Redline Lightweight shockproof oil, and haven't had a crunch since (been in for close to 10,000kms now). Its also both GL4 and GL5 approved so very universal for many cars. Some use MT90 or a 50/50 mix of MT90/Shockproof. Its not cheap stuff but can guarantee it'll be a hell of a lot cheaper then a new gearbox.

Redline Lightweight Shockproof Gear OIL 1 Gallon 3 785 Liter | eBay

That will be enough to do a full swap and some for next time. A lot of people are surprised at what an oil change alone can do (myself included).

[h100vw]

Gavin, no spruiking required. The APR tune (bought on special) was a practical thing as I shared the Polo with my son for 12 months whilst looking for a new ride (now in C63 with a tune ). APR offered easy switching between full tune for me and stock for the P plater. You were the first thought for post front mount and down pipe tune. Blatant plug - need cheap down pipe.

I could have set you up with a way of switching but not quite as simple as APRs.

It's a shame but there's no really cheap way of getting a downpipe. Off the shelf I think only Milltek do one. So I'd probably advise looking around for a place to make you a custom one. Coated mild steel is more than adequate and saves a pile of money.

[earth2dallas]

Thought i was in the same situation about 8mths ago - My 2007 Polo gti was crunching 2nd.... After heaps of research I filled with some G 070 726 A2 (bought from VW dealership)..... Honestly has not crunched once since that day! Very happy. Good luck...

[GRP]

Changed gearbox oil.

Redline MTL. Emptied - it was clean looking oil. Fill with Redline - warm up and flush. Fill again with Redline. Not surprisingly, light metal flecks in oil but far less than what I suspected there would be.

Noise is still there but quieter and gearbox is smoother.

No way the GTi gearbox will take 2 litres of oil. About 1.7 max with car on a good angle. STM Tom Thumb pump made the fill easy.

Tried making a 17mm hex out of a wheel stud. Needed weldiing to hold and I could not be bothered. Bought a Total Tools own brand 17mm inhex spocket for $9.95. The inhex socket is a much nicer fit than the wheel stud.

With the quoted cost of gearbox rebuild/replacement the GTi will remain as is with no punishment given to first gear.