I'll be a newbie again and ask some MT Qs

[Buurin]

After posting tons of useful stuff here including details of my HID retrofit, I'll play a newbie again and post a question of my own.

It has been almost two years since my manual swap. Ever since the swap I have had problems downshifting from 2 to 1 with the car in motion. When slowing down I have to stop the downshifting at 2 and just go neutral for the final stop. Well granted the tranny came from a yard and I have a TRD short shifter. The shifter bushing was replaced pretty late with roller blade bearings (which is documented elsewhere on here).

The tranny oil I used during the swap is Royal Purple GL-4/5 75w-90. The shop I had my flywheel resurfaced sells them for $7 a bottle versus $15 for MT-90 elsewhere. There is also an ancient bottle of 75w-90 synthetic blend gear oil in my garage that seems to be mostly unused. There are reports that GL-5 oil eats yellow metals that are mostly in synchros, yet my manual says I can use either GL-4 or GL-5, and my RP says it's compatible with both on the bottle.

Since it's almost time for an oil change and the gear oil have been in there for two years and I am seeing no improvement with the 2-1 downshift issue, should I drain the gear oil and have a look? Between MT-90, this fill, and my synth blend, what should be my plan here?

[Downhillzze110]

i'd drain your fluid and keep an eye out for metal flakes (possibly CHUNKS)
if you see chunks or A LOT of flakes your synchros are going the way of a free market owned General Motors

[Chris Corolla S]

I don't think there is anything wrong with your tranny.

Most cars have trouble downshifting to 1st unless the car is stopped or going very slow.

Old cars you totally had to come to a complete stop to get into first period.

In my corolla I can down shift to 1st below 15 mph but below 10mph is best. This is how it is supposed to work.

There was a big thread on here a while back about downshifting while comming to a stop and the end consensus was this: The brakes stop the car that's their job.
The only reason I downshift to 1st is if I think I might have to go forward again like in slow and go traffic or a light about to go green before I can stop. Once you are in 4th or 3rd and cruising, you should just use the brakes to slow the car and pop it in nuetral before the car starts to get stally(depending on what gear you are cruising in) and stop the car in nuetral. I usually don't downshift past 3rd if i am comming to a complete stop.
If you do need to go down to 1st double clutching helps a lot. So: clutch in, shift the car from second to nuetral, clutch out and back in (this spins the tranny up to the speed of the motor), shift into 1st. This makes it easier in my car. Older trannys get a little notchy that's just how it is unless you baby the crap out of it.
I think as long as you use a quallity gear oil it won't make THAT much difference.
I have redline MT-90 now and it smoothed things out a LITTLE BIT from the Mobile One 75-90 but overall it worked the best when it was brand new and had the crappy stock gear oil in it

[rolla99oshit]

i THINK its very hard for almost every car to downshift from 2nd to 1st going at around 2000+ rpms in second gear. I drove my cousins 2007 bmw 3 series, and same story with his car, i dont know maybe his car is messed up but im pretty sure he maintains it. So i shouldnt worry about it. Also you gotta remember that first gear is the strongest gear so millimeter of the clutch has to be pressed through the floor, so its better to slow down in second then throw it in neutral

[Chris Corolla S]

Originally Posted by rolla99oshit

Also you gotta remember that first gear is the strongest gear so millimeter of the clutch has to be pressed through the floor, so its better to slow down in second then throw it in neutral

wtf you lost me on that one

[rolla99oshit]

lol i meant the clutch has to be pressed very very hard lol

[Downhillzze110]

man, how tired were YOU rolla99 when you posted that?

[Chris Corolla S]

Originally Posted by rolla99oshit

lol i meant the clutch has to be pressed very very hard lol

Um no it doesn't.
Clutch effort should be the same regardless of gear or speed.

[danielekfuj]

have you checked your clutch fluid? it can somethimes get contaminated with clutch dust, and make shifting more difficult or lead to other problems.

[Buurin]

Originally Posted by danielekfuj

have you checked your clutch fluid? it can somethimes get contaminated with clutch dust, and make shifting more difficult or lead to other problems.

I think both brake and clutch fluid both look like piss So I bought a litre of DOT3 and I'll drain and fill the clutch system come next oil change, in time for the track.

That and inspect the gear oil. I also bought all the MT90 I need.

[danielekfuj]

shouldnt be too bad then. I checked mine and the fluid in the MC was so dark, it looked like used oil.

[fishexpo101]

Buurin - I woundn't worry about it, I'm with Chris Corolla S, sounds pretty normal to me. My Matrix won't go into first until I come very near a stop or crawling speed.

Since you've got two years on the fluid - I'd say go ahead and drain and refill it. Might have all sorts of crap floating around there from the previous owner in there. Can't hurt to flush out the brake and clutch master cylinder and bleed the system as well.

Adjusting the clutch pedal might help as well.

I don't think there is any clear answer in the GL4 vs GL5 debate. Some swear that GL5 will eat brass faster than GL4 fluid - that might be the case, as some testing has shown that some fluids will etch brass test plates. But it was also shown that it was more with the formulation of the additive package that had an influence in yellow metal wear than whether it was a GL4, GL5, or composite formulation. I'll try and find the link.

In my manual transaxles - I run Redline MT-90 (GL4) almost exclusively. Little on the pricey side, but I've never had any issues when using this fluid. Sometimes I can get a decent price break (~$10 bottle) from a sale or promo - I usually stock up on it then.