Question about my 5 speed

90turbo1

Registered User
so I have been driving the car more and more now. and its a 1992 5 speed car.

i just have a couple of general questions.

I filled with GM synchromesh fluid, some say use a friction modifyer and others have said they skiped that. What modifyer do I need to get and what advantage does it have?

the other question is I have a b&m shifter installed and love the short throws but it seemed to have made the actual gear change stiffer, is this normal or something that can be adjusted?

the trans shifts like my old rock crusher 4 speed that was in my 1975 Trans AM... ha ha it doesnt grind, and will go into gear but i must be very carefull when shifting to do it with any smoothness. I guess I have been spoiled with my BMW manual trans that will almost guide itself into next gear and feels like there is some precision in its design.

thanks
 
I used the Pennzoil Synchromesh and added a bottle of Ford Friction modifier a couple of months ago. Seemed to help at the time, and was better when car warmed up. The last couple of weeks, it becamse difficult to shift into first again. Seems like i have to play with it sometimes...sometimes it likes when i favor to the left of first, then other times to the right of first. Other times it goes right in. Also, when i have difficulty, and I try to go into second instead, i may might have the same issue as well.

I looked at the fluid in the master, and it seemed liek it could have been low last night, but it was dark and i couldn't see if tehre was a fill line. Haynes wasn't much help. The fluid looked really dirty though. I was thinking of adding or maybe bleeding....

I had the B&M shifter in my '95 a few years back and I loved it...i should have kept the shifter when i sold that one!

I have no grinding at all in any gear.
 
I bought my friction modifier at Napa...Equa-Torque, I believe. It smells bad. :p

When you add the friction modifier, you are actually decreasing the friction coefficient, making the oil "more slippery". The benefit of this is that your synchros (and other parts) while not wear as quickly. Also, it should make the transmission more efficient, being that there is less energy wasted from "parasitic" loss - just like using a lighter weight oil in the car's motor. The down-side (I currently believe) is that the synchros will not engage as fast (since they depend on friction to match the gears), so it will slow down your shifting.

ON THE OTHER HAND....

I'm a little confused on how adding friction modifier would help a transmission shift better with worn synchros, but many claim (on the SCCoA) have claimed that it does. Maybe the frictional forces opposing the synchronization of the gears are decreased moreso than the forces required to match the gear speeds - resulting in improved shift feel and speed. I dunno! :confused: I'm not sure who might be a tranmission lube expert around here...maybe they'll chime in. :D
 
I guess the original thread was meant for shifting while car is moving.....

My problem is when i am sitting at a light in neutral, and try to go into first. While moving, mine is pretty smooth.

Everything you said makes sense!
 
OK the modifyer is worth a shot. how much should be added to this transmission.

I believe I have some from when I serviced a ford limited slip rear end (is that the same. like a 2 oz bottle????)

anyone have a ford part number that they use?

thanks again
 
I had an older bottle, but I think it was 4.0 ounces as well. One ounce per quart of fluid I thought was the mix?
 

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I filled with GM synchromesh fluid

You get get the GM synchomesh with and without friction modifier.

From what I have read and have been told. All synchromesh fluids excluding GM do not come with friction modifier.

If you have OEM blockers or carbon fiber blockers you should have friction modifier added to the fluid.

If you have brass blockers friction modifier isn't needed.

I have the carbon fiber blockers and GM synchromesh with friction modifier and I had to add more friction modifier. 1-2 and 2-3 shifts were very hard and liked to grind when I had just the GM synchromesh in it, 1-2 improved greatly when I added more friction modifier. I think my transmission builder didn't check the tolerances and the slider for 2-3 and that is causing my 2-3 shifting issues. :(
 
If you have OEM blockers or carbon fiber blockers you should have friction modifier added to the fluid.

If you have brass blockers friction modifier isn't needed.
The friction modifier allows the fiber lining of the ring to slip more when it engages the gear cone. Then when the shifting action finishes pushing the slider over the gear, the FM allows the 2 surfaces to slip against each other slighty so that the slider's teeth mesh more easily into to the blocker teeth + gear teeth. Its this slight slip that results in the smoother engagement of the slider.

With a brass blocker, obviously there is no softer fiber to slip against the cone, hence adding friction modifier won't do anything at all to help with that shifting. Note BTW, that because it has a tighter grip, there is not much slip to help align the teeth. The brass blocker will cause more wear on the slider ring, gear cone face, and the blocker itself.

Oh and for clarification, all blockers are made of brass... when we talk about "brass" blockers what we really mean is the unlined blockers.

I have the carbon fiber blockers and GM synchromesh with friction modifier and I had to add more friction modifier.
Same here. But I might add, I don't know that the FM that I used affects the carbon fiber liner much. I'm generally pleased, but there might be something better out there for CF.

I think my transmission builder didn't check the tolerances and the slider for 2-3 and that is causing my 2-3 shifting issues. :(
Could also be dull teeth on the slider ring which you really can't do much about.
 
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You get get the GM synchomesh with and without friction modifier.

From what I have read and have been told. All synchromesh fluids excluding GM do not come with friction modifier.

If you have OEM blockers or carbon fiber blockers you should have friction modifier added to the fluid.

If you have brass blockers friction modifier isn't needed.

I have the carbon fiber blockers and GM synchromesh with friction modifier and I had to add more friction modifier. 1-2 and 2-3 shifts were very hard and liked to grind when I had just the GM synchromesh in it, 1-2 improved greatly when I added more friction modifier. I think my transmission builder didn't check the tolerances and the slider for 2-3 and that is causing my 2-3 shifting issues. :(


so I used GM synchromesh GM label on bottle and all. so that doesnt have a friction modifyer then?
 
so I used GM synchromesh GM label on bottle and all. so that doesnt have a friction modifyer then?

I'm assuming if doesn't say it, it doesn't have it. Call a GM parts department and give them the part number off the bottle and ask.
 
I got the syncromesh in two trans with aftermarket Equa-Torque friction mod. One I drive daily and it has 150,000 miles on the trans itself. I presume it was rebuilt somewhere along its life cycle as the blockers were In good shape...Both have a B&M shifter and the one with the higher mileage is quicker and smother then the one with 85~K, Also rebuilt. The one gear with the Carbon Fiber lined syncro will grind if I am not careful with clutch and the shifter, but that syncro blocker is in 4th so I dont need to shift that fast in that gear.
 
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so I used GM synchromesh GM label on bottle and all. so that doesnt have a friction modifyer then?

GM sells two part numbers, Bottles look identical. One cost $10 bux the other $15. The part number will tell you if it does. Assuming you look up the part numbers that have been posted in the past that references the bottle with.
 
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