gearbox problem

[drifter17a]

does any one have issue shifting from 2 to 3 ?

If i shift slowly it is fine but when flooring and trying to change quickly it doesn't normally go into gear. I heard short shifter makes it worse. Please advise.

 

I was thinking of buying below but tuner told me it will make it worse and wear the bushing .

 

https://www.ebay.co.uk/itm/CUBE-Speed-Short-Shifter-For-Nissan-Skyline-R32-R33-R34-RB20DET-RB25DET-RB26DETT/323789024509?hash=item4b63546cfd:g:1lkAAOSwgAJa2Ksc

Edited May 2, 2020 by drifter17a

[Ben C34]

Worn synchros, yes it has happened before. It's not a problem with the shifter, so replacing that won't help, and your tuner is right, shirt sgufters are harder on synchros

 

 

[Duncan]

A gearbox with worn synchros will have problems shifting gears, generally 4 to 5 is worst but it depends how the box has been treated over the years

The faster you shift, the worse the crunch will be, potentially including missing the gear altogether. Short shifters help you physically move the gear selectors faster so yes they make the problem worse.

The only proper fix is to pull the gearbox out and have they worn synchros replaced. In the meantime, redline lightweight gear oil (smurf's blood), nulon G70 (or whatever similar is available where you are, there is no location in your profile and you didn't say) or even just heavier oil generally can help

[drifter17a]

I am in the uk, cool will look into changing oil first

[KiwiRS4T]

And make that 2/3 change carefully or you will be needing gears as well as synchros.

[GTSBoy]

In other words, slow down the shifts.

[drifter17a]

Is it hard to rebuilt gearbox diy?

 

first time i would open a gearbox but seen loads of videos doesn’t seem like difficult task

 

does it need specialist tool?

[GTSBoy]

You need good circlip pliers and some pullers and stuff. The difficulty is "rebuilding gearbox diy", is being able to source the parts you need when you open it up and find 50 different things are f**ked.

[drifter17a]

Doable then

 

is there another car box which fits r34 and gives you upgrade without lots of custom changes?

[GTSBoy]

1 hour ago, drifter17a said:

is there another car box which fits r34 and gives you upgrade without lots of custom changes?

No.

[Duncan]

3 hours ago, GTSBoy said:

You need good circlip pliers and some pullers and stuff. The difficulty is "rebuilding gearbox diy", is being able to source the parts you need when you open it up and find 50 different things are f**ked.

Personally i get a specialist to do gearboxes, because the key point here is "50 different things are f**ked". Some problems would not be obvious to non-professionals. Obviously pulling apart and putting back together is just following a set of steps carefully, but there is no point doing all that and then realising you didn't see one or more issues.

[drifter17a]

I am thinking of putting redline heavy 75w-140 .

 

https://www.opieoils.co.uk/p-1023-red-line-heavy-shockproof-gear-oil-75w-140.aspx

 

reading online some say it is not good for my gearbox as it will be difficult to shit. currently have castril gl 4 75w-90.

tuner recommended this and looking online some people say it has fixed the syncro issue. My issue is from 2nd to 3rd and 4th to 5th if shifting quickly. I want this to be in box for a year or two before buying a recon one and replacing it. 

I don't think lightweight or super lightweight work for me .

Spoke to redline and they said use MT-90 but again that is same as my castrol so think the heavy shockproof is way to go. has anyone used this /?

[KiwiRS4T]

The answer is to not shift quickly on the dodgy changes and to double de-clutch appropriately.

[drifter17a]

understood however does the oil help here?

Some swear by it saying it fixed all crunching and syncro issues?

[BK]

If that oil helps you, your box is pretty stuffed. Redline website "NOT recommended for most synchro applications".

You're in a situation where you will have to try out something to see if it improves your situation. That said, if you need any other oil than what is supposed to be in that box, you are really only just covering up a problem that needs fixing.

 

[admS15]

Probably better off trying the redline mt90 and add some nulon smooth shift. If it's still no good, then the only ither options are a rebuild or replacement gearbox.

[GTSBoy]

I have lightweight in my box. When it was first installed it would not shift with the engine running at all (with normal gear oil). Redline brought it back.

Of course, as a consequence of owning an ALFA for many years, I also know how to manage a baulky gearbox. Learning to drive properly >> bandaid fixes & snakebloods.

[joshuaho96]

If the synchros are on the way out some lightweight shockproof will help but only delay the inevitable. Don't shift quickly, double-clutch your downshifts. You will be able to get a bit more out of the transmission before rebuild. Don't try to DIY a transmission rebuild unless you feel like taking the transmission out multiple times. You will save a lot of money if you're willing and able to drop the transmission yourself, that's a good chunk of change right there.

[drifter17a]

33 minutes ago, GTSBoy said:

I have lightweight in my box. When it was first installed it would not shift with the engine running at all (with normal gear oil). Redline brought it back.

Of course, as a consequence of owning an ALFA for many years, I also know how to manage a baulky gearbox. Learning to drive properly >> bandaid fixes & snakebloods.

i take it your box was worn so it won't shift and redline brought it back ?

[drifter17a]

23 minutes ago, joshuaho96 said:

If the synchros are on the way out some lightweight shockproof will help but only delay the inevitable. Don't shift quickly, double-clutch your downshifts. You will be able to get a bit more out of the transmission before rebuild. Don't try to DIY a transmission rebuild unless you feel like taking the transmission out multiple times. You will save a lot of money if you're willing and able to drop the transmission yourself, that's a good chunk of change right there.

new refurb one is around £1300 and want to kill this, buy one next year and then swap.

I can then rebuild mine and learn something . I can then keep as spare or sell it .

 

Have seen many posts stating to use lightweight but some other saying heavy weight. confused now.