DmcL

is 4th in particular more of an issue than other gears? a quick google search brought up loads of results of people having issues grinding or crunching into 4th in anything from a classic to a new age 5 speed.

secondly is there anything that can be done to reduce or if lucky stop it happening short of a box out job or box swap? also is there a general idea of how long before a crunch turns into a bang?

curious as my 06 WRX has crunched 4th on anything other than granny shifting since i got it last year. if giving it the beans then it will crunch 4th every time, if accelerating moderately and shifting a little slower it still will crunch maybe 70% of the time, literally only way to garauntee no crunch is to drive low revs and shift into 4th super slowly. i can feel a bit of a notch with the crunch as it grabs the gear as well. so far the crunch hasnt got any worse, nor has the feeling changed. also it will crunch into 4th downshifting some of the time depending on how quick or in what circumstances. also seems to do it less before the cars fully warmed and very occasionally it will work fine. most notably after i botched a shift and actually grinded 4th on the neutral side. after that it oddly behaved perfectly normal for maybe a day and a half or so.

not sure when/if the gearbox fluid has been changed previously but the car has 70k on the clock at present and changing the fluid in the box is quite high up my to-do list as it cant hurt and i read somewhere that box fluid should be a 30k job, plus theres bound to be filings in there from all the crunching as its happened loads since i got the car and god knows how long it was doing it before i got it.

so whats the lowdown here? i could live if it went on for a good while as is and one day i just lost 4th and had to make do with 3rd and 5th until i sorted a box or box rebuild but if the box would likely completely **** itself then id be better trying to ferret away some funds for the impeding rainy day.

sens3i

iTrader: (1)

Ive been advised for notchy boxes the best temporary fix is to replace the gearbox oil; Ive just bough 5 quarts of Redline 75w90 Shockproof Lightweight. £23 a quart but its good stuff!

Once my box goes completely in my classic it will be time for 6spd conversion!

Cpt Jack Sparrow

iTrader: (14)

I had a crunch from 3rd to 4th that started 6 months after getting the car.

When I then looked into the last service invoice, the gearbox oil used cost less than £5 per litre...

so I bought some decent stuff from Oilman, got it changed and crunch went immediately and has never come back.

oilman

iTrader: (9)

Glad the oil worked out for you.

DmcL, do you know what oil is in the gearbox or when it was last changed?

Cheers

Tim

DmcL

there is no record in any of the cars history of the oil ever being changed in the box. its a decently documented history so id be inclined to believe it may still be on the original oil.

i have a trade account with opie as it stands. just ordered 6L worth of motul 300v power 5w-40 as well as 1l of silkolene pro boost for a rainy day not even 3 months ago. i had intended on doing the box oil around that time as well but im sure you know 300v power isnt the cheapest but from what i see has always given good results in UOA's (used oil analysis for anyone wondering the abbreviation) when compared to most others. so far can not fault the motul 300v power 5w-40, can see no notable oil usage, no issues and engines running great. my only complaint is that my oipe air freshener no longer smells.. sort it out! lol

regarding box oil for the WRX 5 speed, im told id be better NOT going for a shockproof as there is no front LSD and its not an STi or something to that effect. is this actually true? based on that information i was looking at castrol syntrax 75w-90 as have been informed it would be suitavble for the box as well as the rear diff. can you advise if thats a good choice or is there something better suited to the box or box and diff?

oilman

iTrader: (9)

Hi

If you've got no record of the oil being changed, then it's quite possible that just a change of oil will sort out the problem. The Lightweight Shockproof would be fine for your car, although I doubt you'd need something like that. I'd probably go for the Motul Gear 300 as a top choice or the Castrol Universal as a cheaper option.

http://www.opieoils.co.uk/c-673-75w-90-gear-oils.aspx

Cheers

Tim

DmcL

considering i went for 300v power for engine oil which i think is one of the most expensive if not the most expensive then im hardly going to sweat on a few quid over gear oil.

would the shockproof stuff be of any benefit over the motul gear 300? i do intend on bringing the car up into the mid 300bhp bracket from its current 256bhp and i do like to shift quickly when im giving it some beans.. id like to install a short shift kit but need to determine whether that would increase the odds of gearbox problems or blowing the box once theres a bit of power in it.

slightly off topic but what would you recommend for an old 325i sport gearbox? there were 3 variations on fluid requirements and one of them required ATF. i dont remember off hand what mine was when i fitted the box. i seem to remember red fluid in it but i may be thinking of the previous manual box that was in it. everything works fine and no problems with the box, however, i have a modified Z3 M coupe gearstick with an extension and the Z3 M stick reduces shift throw about 70% over the standard stick. i also made/fitted a clutch stop to remove the dead travel which also helps in shift speed and i find that on very rare occasions on super quick 1st to 2nd sprints it seemed as if i was beating the syncro so to speak and id get a bit of a crunch/****** into 2nd. only happens on extremely quick shifts though, so quick i couldnt manage to do it every time i tried. the box is a getrag 260 if that helps.

oilman

iTrader: (9)

Hi

If the power is going up by that much, perhaps the Lightweight Shockproof might be a better option than the Gear 300. I wouldn't use a semi-synthetic, like the Castrol Universal, for that.

Which 325i was the gearbox out of? E30, E36 or E46?

Cheers

Tim

DmcL

what shockproof would you recommend given my plans for the WRX? also would it do for the rear diff as from what i gather its a viscous LSD.

the E30 box is from an E30 325i sport. as said there were 3 variations in fluid requirements in the E30's getrag 260 boxes, two were manual fluid and one was ATF. is there a one size fits all?

oilman

iTrader: (9)

Hi

I would use the Lightweight Shockproof and that would be fine for the diff as well.

According to my data, all of the E30 boxes are fine with a MTF and the best proven options are the Red Line MTL, Amsoil MTF or Fuchs Sintofluid. The Millers TRX 75w-80 and Motul Motylgear are good alternatives.

http://www.opieoils.co.uk/c-670-75w-80-75w-85-mtfs.aspx

Cheers

Tim

DmcL

ok so no lightweight shockproof in particular? i just flashed a stage 1 tune on the car yesterday and am already looking into adding flat foot shift to the tuning. want to make sure im using the best i can for my 5 speed.

re the BMW box, folks swear the ATF box must use ATF, advice is not so strict on the two MTL variants. i dont remember the exact reasoning but i think the differences in fluid were something to do with syncro's being made from different materials or something like that.

oilman

iTrader: (9)

Hi

There is only one Lightweight Shockproof.

http://www.opieoils.co.uk/p-1022-red...il-75w-90.aspx

I've not come across an E30 that requires ATF before (so I assume they aren't common), but I've just checked through some data and apparently, if there is an orange label on the box, it needs an ATF. The best options for that are the Amsoil ATF, Red Line D4 or Fuchs ATF6000, although the others are fine as cheaper alternatives.

http://www.opieoils.co.uk/c-771-dexron-iii.aspx

Cheers

Tim

DmcL

re WRX, ok thanks.

as for the bmw, i painted the box before fitting and cant remember if it had a sticker or not. two of the variants had a coloured sticker and one had nothing. looks like it will be under the car time before i look at fluid for the bmw.. ill need to scrape the paint off to see what it is.