Mitsubishi Synchro Problem?

[FTO-UK]

I recently bought myself a Mitsubishi FTO - this is a small Japanese-market front-wheen drive sports car with a 2.0l V6 engine . Its has a 5-speed manual transaxle and the car has only 20k miles on it (its a very clean and 'tight' car so could even be genuine miles....).

Anyway, the engine, suspension etc is great. I have a small snag with the gearbox. Its rather 'notchy' when cold. When warm it tends to 'catch' third gear synchro when changing up 2-3. Strange thing is that I can downshift as fast as I like 4-3 or 3-2 and there is no problem, its perfect, its just the upshift where there is a problem.

If I change up slowly from 2-3 (with a pause at neutral for a second or two) then its OK. A fast 2-3 change at 4000 rpm gives a definite crunch as it goes into 3rd.

I changed the gearbox oil for Redline MT90 - this is the recommended grade for the gearbox (75W-90 GL-4 Synth.) - but no improvement. I also bled the clutch and checked its adjustment, but it seems fine. I feel sure that the car shifted much better when I first bought it - but I have no idea of the grade/spec of the oil that was in there (the car was imported to the UK from Japan and I don't have the Japanese service history).

Someone has suggested the cable linkages from the shift lever may need adjusting - is this a possibility? Would a thinner oil (e.g. 75W-85 or even 70W-80) give any improvement do you think? Or am I looking at a 'box strip and repair?

 

[MolaKule]

Since you are a fan of Redline, try the 50/50 mix of Reline MT90 with MTL.

Or you could try our MTL-P.

Make sure the shifter cable is registering the right gear and is not attepting some "intermediate" position.

 

[FTO-UK]

Thank you for your reply MolaKule. I am actually in the UK (England) and I don't think your oils are available over here, are they?

I am not a special fan of Redline, but they are fairly easily available in the UK. GM Synchromesh may also be available, but I have not specifically looked for it.

 

[MolaKule]

We're not available "Off-the-Shelf" but we ship anywhere in the world.

 

[tdi-rick]

you could try Molakule's suggestions, or another alternative is Castrol Syntrans, which is Castrol Oz's prime recommendation for high performance Mitsu transmissions.

 

[FTO-UK]

I had thought of using the Castrol. I am curious as to whether going from my present 75W-90 to a 75W-85 can really make any noticable difference to gear shifting. Is that difference of '5' in the hot oil weighting really going to be significant in everyday driving?

BTW, MolaKule - I note that you ship oil internationally (although I might have to wait 6-8 weeks!). Your prices aren't too bad, even with the shipping, so I may buy a gallon or two. My wife runs a Nissan Primera (G20 equivalent) that also has a somewhat notchy box and would probably benefit from a higher-spec oil.

 

[MolaKule]

FTO from UK,

We can ship 1-2 weeks international but the shipping costs are astronomical, about 3 times the cost of the product.

Our regular 6-8 weeks shipping has averaged three weeks, depending on how many times customs' checks it.

 

[mechtech]

First, I'll vouch for S.F.s products. Well, OK, I've only tried their MTL P , but it's the best I've used. I have dealer experience, and my own shop for 30 years, BTW.
That clutch adjustment bears looking into, as well. Give it a slightly longer travel [for more disengagement], and take the slack out of the master cyl. pushrod. Give it a hair of preload into the master cyl., to take out the dead space travel.
The heavy flywheels that Mfrs. put in their cars to make the average citizen less likely to stall the vehicle, makes you shift like you're in the first day of driver's education.
They also install a wavy Marcel spring in the clutch disc, that doesn't disengage readily, but is smooth in engagement.
All that said, contact S.F. and see what is suitable for your gearbox.

 

[FTO-UK]

OK, you talked me into some SF MTL-P.

Anyway, back to my question above - can anyone answer this?

"I am curious as to whether going from my present 75W-90 to a 75W-85 can really make any noticable difference to gear shifting. Is that difference of '5' in the hot oil weighting really going to be significant in everyday driving?"

Regards FTO-UK

 

[mechtech]

They're very close in weight. Depending on the temperature, the 90 may be thinner than the 85.

 

[MolaKule]

Forget weights and think kinematic viscosity. The 75W90 is usually at least a viscosity of 15.0 cSt and our MTL-P is 11.5 cSt, a major difference. So yes there can be a large difference in shift quality due to viscosity. I had discovered some time ago that in my Nissan, anything over about 12.0 viscosity did not shift well even when the same type of Friction modifier was present.

The main difference in shift quality comes about by the mix of synthetic oils and the friction modifiers; assuming your shifter is calibrated correctly and your clutch is fully disengaging when changing gears.

 

[mechtech]

Mola - Don't forget that we older folk like to use technically incorrect, outdated terminology!

 

[MolaKule]

My apologies mechtech.

Seriously, we highly value your real-word, mechanical information.

I have found that it takes a good mechanic, a formulator, and a good oil analyst to work-up good lubes.

 

[mechtech]

What would Moe be, without Larry and Curly?