ST185 Close Ratio G/Box > Non CR-Rear Diff Change Needed?

[KE25-KP30]

Hey guys, I've got a ST185 GT-Four Rally, which is a narrow body version made for rallying (funny enough!). It came with the close ratio E152F which is sadly not in a good state (graunch into 2nd, won't go into 3rd) so I've pulled it out, and have a stock GT-Four box to go in.

The question is, do I need to look into changing the rear diff to match, or are the front diffs the same on all the GT-Four/ E15*'s which in turn will mean no change needed?

Also, has anyone here done a gearbox overhaul in a garage (i.e DIY)? How difficult and what are syncro's etc worth?

Thanks a tonne!

[RunningRich]

Every GT-Four uses the same rear diff ratio therefore all the gearboxes are interchangeable.

Have a read of the manual regarding rebuilding. A lot of specialised pullers are needed on this box.

Alfa boxes are very different, apart from the bolts you can literally disassemble them with a hammer, a punch and a pair of pipegrips.

[strx7]

synchro's are usually $200-300 each

[KE25-KP30]

Awesome, thanks for that! Yeah I can imagine that they would be a mission.

Ouch, does that mean that parts alone are going to be around the grand mark?

Thanks again

[TRD Man]

Running Rich is correct. Final drives are the same.
The gearbox is worth fixing. The ratios 1st through 4th are quite different from a regular GT4 and you'll really notice it.

[KE25-KP30]

Oh really - I did wonder if that was the case, and reading around seems they are slightly rare. Maybe I'll save it for a rainy day!

On another note, if it wouldn't go into third when the car was running, does that point to a shot syncro, or worse?

[strx7]

synchros are probably cracked so when the cluster is rotating they expand, like trying 12 groove into a 13 groove hole.
when we rebuilt my rx7 gearbox it was like that, it would hardly ever go into 3rd and it was cracked right thru in one place and nearly thru in about 6 others

and yes that estimation is PER synchro. Toyota synchros are pretty pricey. Rebuilt my bosses landcruiser box at work here and new synchros were over a grand.

[Boosted_162]

If your keen on selling it....im keen!!

[RedMist]

I'd read reviews on the box and a majority of those who use them on the road want rid of them. On paper they look a little weird as well with a short 4 cluster then a big jump to 5th. I would think they work well for what they were designed for... rallying.
Isn't the 152 part of the generation of ST165/185 boxes that had weak synchro's and hence the switch to a tripple synchro in the 205?

[KE25-KP30]

Thanks strx7, makes sense!

I wondered if you might say that Boosted_162 - I'll keep you in mind if and when!

Interesting what you say RedMist - when you say rallying, would that "umbrella" general track racing too... I guess you would use gears 1-4 around a track, and the theory is that on the open road it would be like any other and not reving it's head off. I've also read along the lines of the weak syncros... I guess that's why 2nd and 3rd are no go in mine!

Cheers for the replies/input

[Prymal]

have a looksee around for a 205 box , and shelve the close ration one in the shed and piece t back together when you can

you could find a runner 205 box , for the price of rebuilding the one you have - And it will be stronger.

[KE25-KP30]

I've got a stock 185 box for the time being, but a 205 would be ideal. Aside from the syncros, are they much different to a 185 box? i.e stronger in general?

[Prymal]

bigger transfer case ( from memory ) no FWD limp mode selector - better syncro's , different gear rations , basically unbreakable unless your an idiot or race/thrash them

[Twolitre]

Do you know the history of the ST185 box you are going to install into your celica? It could be just as bad as the one you're currently using and it would suck to go to all that effort for no gain.
An ST205 box would be ideal but they aren't cheap or easy to find and you could probably rebuild your close ratio box for the price of a 2nd hand ST205 box.

[Prymal]

that depends on the syncro set used ..

the St205 ones and RC ones arent exactly Cheap .....

[KE25-KP30]

Wow, didn't realise the 205 boxes are that tough!

No ideas on the history of the box and definately good point, but I'm going to take the chance on it anyway and so long as it's drivable I can look for another one or rebuild the CR box.

When you all say a 205 box isn't cheap... what sorta money are we talking?

[DeeCee]

st205 box ranges between $300 - 1000 or more. Very rare to see a st205 around the $300 mark or below and commonly are seen on TM at the $1k mark.

[KE25-KP30]

Ouch! Thanks - I'll start to keep my eyes open for one.

[sergei]

I have imported complete st205 gearbox (including transfer case) and rear diff for $750 from japan (all done about 50k), shipping was free as I just asked them to put in one of the cars that the company I worked for bought.