ok, so I traded this guy for this tranny about 2 years ago and I just now got my car running. Well we havent driven the car yet but had it up on jack stands taking it through some gears. well it runs at 3k rpm at 50 mph in 5th gear, is this normal? the rpm seems awful high. also my dad said he noticed that the wheels did not turn independently of one another, kinf of like the transmission was acting as a straight axle? is this normal? He said that the final drive must not be stock from honda and that the tranny has been opened up before? any help it greatly appreciated.

Cory

 

If you have LSD the wheels will turn together when on jack stands. LSD makes it so that one drive wheel will not turn more that 10% faster than the other drive wheel- this is when there is a load on the drive train if there is no load(like when on jack stands) the wheels will turn together. As far as the rpm and speed I would not look that far into that until you try it on the street.

BTW 10% is an estimate

 

that is pretty close to the 4th gen tranny with the 4.64FD, but the M2B4 is not compatable with aftermarket final drives, so unless its custom, i'm not sure, you're sure its an M2B4?

and speed/RPM is the same in the air or on the ground

 

im sure its an m2b4 case because of the stamp. so I am going to assume that its an m2b4 FD along with all the other gears. My dad said when on jack stands, at 70 mph in 5th gear it revs at 3700 RPM. that seems normal if you ask me. He is gonna drive it on the road and see how it does. Anymore ideas is great

 

yeah im not sure the exect rpms sence mines been in storage but my m2a4 is at 3k at 50 witch is the same as yours so everything sounds fine. 70 is about 4 witch is also what u have.

we both have jdm transmissions you just have a lsd and i dont, but both should have the same gears

 

wtf is this load of bullshit?

You need to stop going from thread to thread and posting your crappy misinformation framed as facts.

Cory, you're probably fine here, just get it on the road and see what you get. The rpms sound about right.

 

What is incorrect about what I was saying

 

A limited slip differential (LSD) is a modified or derived type of differential gear arrangement that allows for some difference in rotational velocity of the output shafts, but does not allow the difference in speed to increase beyond a preset amount. In an automobile, such limited slip differentials are sometimes used in place of a standard differential, where they convey certain dynamic advantages, at the expense of greater complexity.

There is that better?

 

gearing is gearing dude, any RPM through whatever gearing is going to be the same output at the wheels. i think you might be thinking that since it requires less load to get to that speed, that it will be different, but it is not. hate to break it to you, but you're wrong. again

 

three cheers for wikipedia!

 

Really so what affect would bigger or smaller tires have on the RPM at said speed? And by Bigger or smaller I mean taller or shorter.

 

its irrelevant, the only speed he knows, and the ONLY speed that anything modified in the transmissions will give him is at the VSS, which goes to the speedometer.

yes, wheels and tires affect gearing, but that will not alter your VSS reading

 

The only thing I was trying to point out is that it could be different when on the road. If I offended you by doing this I apologize.

 

it won't be different on the road, his speedometer will read the same, so unless he is driving by radar traps to check his speed, his speed will be the same for all intents and purposes

 

ok, so the RPMs seem to be about right. But what about the wheels turning independently of one another? Is this because the car was on jack stands? If im not mistaken when turning, the inside tire requires less rotations correct? And the LSD is what allows one tire to turn less than another? I really know nothing about transmissions.

 

the lsd will make them both spin at the same speed and the same time.

 

If this were completely true, you would have a tough time going through corners.

 

that is true. its one down side of a full lsd.

but i dont think honda factory lsd are a full 2 way to b honnest. but your correct i should edit my last post

 

Leave the gran turismo terms out of it :p

A "2 way" LSD as you're speaking of it means that the axles can be locked together both on acceleration and deceleration.

The nature of an LSD is the following: in normal driving conditions it is unlocked, and the axles are free to spin independently. Cory, check this by holding one wheel still and spinning the other.

When the LSD senses slip (when one wheel is spinning a lot faster than the other), it locks the two axles together so that they spin at the same speed. This locking is very pronounced in honda LSDs, it used to jerk the dash in my car at times. If turning and slipping, the LSD engaging can cause more slip if you're not ready for it. In that case you're best off pointing at the turn exit and praying.

 

lol you knew what i ment though haha

 

yeah, you were just thinking about a full on locking differential or "locker"

these generally aren't used on fwd cars, because turning requires one wheel to spin faster, and some lockers do not allow for that

 

so...my dad got the car running really good. But he says the car jerks really bad in turns. He thinks the differential might be bad but from what I read this is normal in Hondas? So what do I do now? He said it only jerks and shakes in the middle of turns.

 

Any loose suspension pieces?

 

Shift bushing fell out yesterday so have to work on that today

 

shouldnt be. needs new ball joints tho and an alignment. I should know more after it gets aligned.