Redline Lightweight Shockproof Or Redline Mt-90?

[daxter]

Hi, which redline oil is better for older transmissions, 'Redline Lightweight Shockproof' OR 'Redline MT-90' ?

1st to 2nd sometimes crunch's, guessing the synchro is worn.

Car: R33 GTS25t

Thanks

[CHARGD86]

use shockproof in my rb20 box works killer and is crazy yellow

[MrStabby]

Old/worn gearbox = lightweight shockproof ("smurfs blood", blue)

Good gearbox = MT90 (yellow)

[daxter]

Old/worn gearbox = lightweight shockproof ("smurfs blood", blue)

Good gearbox = MT90 (yellow)

Is MT90 known to help warn synchro's? From what Ive read it seems MT90 is better for GTS25t boxes than lightweight shockproof.

[bozodos]

Bit curious on this one myself, I'd read some conflicting reports around here, though ancedotally, everyone IRL I've spoken to about Redline Shockproof Lightweight reckons it's brilliant on boxes where it's just a synchro or two starting to grind.

[TokyoTaxi]

I've spoken to many people about this over the years and the general consensus is Redline Shockproof Lightweight ( aka Smurfs Blood ) is the best option for RB20, RB25 and VL(T) boxes.

I'm using smurfs blood in my car atm. I used Redline Shockproof in my R32 GTS-t before that ( but have not yet tried MT90 so I can't comment there. ) Both gearbox's were /are in brilliant condition and both crunch 2nd ( sometimes 3rd ) until well warmed so ........

[bozodos]

Mine crunches 4th when it's hot (and VERY occasionally 3rd when being driven flat out) so yeah opposite problem to yours!

[daxter]

OK looks like Redline Lightweight Shockproof is the favourite, will give it ago.

[simpletool]

I'm using MT90 but never used shockproof. I chose MT90 as I thought it has lower friction modifiers or whatever they are called. I thought shockproof wasn't recommended for synchro boxes as it's too slippery.

I change slow or fast and no crunch - but can definitely crunch 2nd and 3rd if you change medium paced.

Edited April 17, 2009 by simpletool

[joeleo87]

im looking at buying and fitting a 2nd hand G/box and rear diff but some1 told me to put some shock proof in there first?

is it worth trying it out? or should i just get another g/box fitted?

the gearss dont crunch or anything but they certainly dont glide in like they should, i have to hold the clutch on the gripping point for longer to get a smooth change.

as for the diff i have some backlash, can u use redline in there to?

[GtstCoupe]

I currently have super light shock proof and has been good, but im about to change to redline mtl and mt90 for the diff. as it appears to be too slipery for the synco to do its job,that being said i havent had any issues but i dont want to the wear them or destroy them.my understanding being too slipery the syncos dont really work too well as the require a little more friction of thicker oil. i have had the odd crunch into 5th but only if you shift slowish.

Redline website says, mtl for box and mt90 for diff, the recomend shockproff for racing and dog boxes etc, basicly think every thing that does no have sycros. but i have had it in for 3 years and its been good, but now ill be a little more at ease and the box will be a little more quite with thicker oil as i found then when changing from mineral to to the shockproof as it is like twice as runny.

Cheers, let yous know how i go.

[some_cs_student]

I've got MT90 in my gearbox and the synchro's don't always work, I think I'll switch it for the castrol brand or MTL oil...

[Crackfox]

I'm about to order some oil to do a gearbox oil change and I'm now facing this problem, which oil I should choose. MTL (which the redline website recommends me) or shockproof lightweight. The car is a 1993 R33 GTST. I do not drive it hard very often at all, and it has hardly any power enhancing modifications. I do use it for alot of short trips so it is often driven cold. The gearbox seems to be fine, though when cold it will sometimes crunch into 2nd if I don't shift slowly and smoothly.

Lots of people seem to recommend shockproof lightweight but it seems to be more race car orientated which my car definately is not so I am hesitant to buy it. Would MTL provide me with better driveability/smoothness or less wear on the gearbox with gentle daily driving and sometimes driven when cold? These are the only things I want out of my gearbox oil, I don't need it to operate well at extreme temps or with harsh shifts at the track because my car won't ever face this.

[my_gtr32]

I recently replaced the gearbox in my R32 Gtr with a brand new R33 GTR series 3 box. Tried Castrol Syntrans first off and found shifting less than great especially when cold. Next up was Redline MT90 and went on a test drive. Straight up it felt great, but the next cold winters morning, not so great until it warmed up. Shifting first to second was difficult.

After this, I tried MT90 with 250ml of Nulon G70. This did make a difference but cold shifting is still not great. I'm thinking of giving MTL a try as its a bit thinner than MT90. Not sure about using Lightweight shockproof in a new gearbox. Used it before in my old box and it seemed very good. These gearboxes DO NOT shift real well when cold even when new. Take my word for it!

It doesn't help when using a Nismo twin plate clutch either, as the syncro rings need to control the speed of the input shaft with the added weight and mass of the clutch assembly for a clean gear change. Not sure what to try next??

[some_cs_student]

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Lots of people seem to recommend shockproof lightweight but it seems to be more race car orientated which my car definately is not so I am hesitant to buy it. Would MTL provide me with better driveability/smoothness or less wear on the gearbox with gentle daily driving and sometimes driven when cold? These are the only things I want out of my gearbox oil, I don't need it to operate well at extreme temps or with harsh shifts at the track because my car won't ever face this.

Which redline website did you use the get the recommendation?

From memory the redline Australia website used to recommend lightweight shockproof for the R32/R33 gearbox

Is your gearbox old?

Is the shifting good?