M5R2 rebuild with hard shifting

hepcat

Registered User
Ok I just rebuilt my M5R2 and was wondering if it takes time for her to break in the syncrose to ease up the shifting into gear, because right now I have to put some pretty good pressure before the tranny will shift into First, Second and Fith. This is with the car running and putting the clutch peddal down and trying to just shift through gears at a stand still. It seems to of gotton a little better with running it through the gears at a stand still. I haven't driven the car yet since she is in the air. I wanted to make sure it works before I drop her and drive my 94 thunderbird sc.

So is this normal for a fresh rebuild?

Maybe I just need to get her on the road and see what happens.

Thanks

hepcat
 
Last edited:
That is not normal. Make sure that your clutch is not dragging. Do the rear wheels want to spin when you put it into a gear?
 
Dragging

XR7 Dave said:
Make sure that your clutch is not dragging. Do the rear wheels want to spin when you put it into a gear?
What would cause the clutch to drag? Are there any adjustments that can be made?

68COUGAR
 
Last edited:
Hmm

Well maybe I didn't get my clutch master cylinder all bled or my new slave cylinder. How many times do you bleed it when it is new?

Also it has a new clutch set as well. When I first got the tranny in gear it did learch forword and then I bled the clutch again and it didn't move the next time I stared but it is still hard to get in gear but didn't learch forward. It does not grind though.


I am also using regular ATF for a few miles and then I will flush it and use that sycromech ATF. People say that works for helping shifting.

Ow if I have the car off I can shift the tranny just fine so that seems good.

Thanks
 
Ya, sounds like you need to bleed the clutch more. Jack the car up in the back and shift gears. If it goes easier and the wheels turn, then Houston, we have a problem. ;)

If you used OE fibre blockers then you need to add friction modifier right away. Regular ATF will damage the blockers. If you used brass ones then it will be fine.

How does your clutch pedal feel? It should disengage imediately with no free play.
 
tranny

The clutch pedal feels good and I am going to lift the back wheels off the ground put it in first and start it and see if the back wheels spin with the clutch in. I have bled the clutch more than 30 times and it should be good and looks good from looking at the slave cylinder from underneith with the clutch pedal floored.

I try what you said and get back to ya.

hepcat
 
Not sure if this might help you, but check my post on the "Non-Tech" Forum tittled "Need Tips, (Clutch Related)" last post was on 6/18/04"
hope it helps...
 
Micahdogg said:
Dave, shouldn't you use MTL on brass blockers and ATF on stock/fiber?

Micah

What I meant to say is plain ATF w/o Friction modifier will/may damage the fibre syncros.
 
I meant the comment "ATF on brass ones will be fine", but didn't you actually say that ATF wouldn't offer enough friction and a MTL would be better? Unless I misunderstood you from our last conversation.

Also, how do you think straight 30 weight oil would compare to ATF and MTL? Cause I've got straight 30 with brass and it sucks, but surely it's thicker than ATF right?

Micah
 
ATF is fine. MTL is better (for brass blockers). ATF viscosity varies from about 30-60 depending on type. MTL is 70. It will be thicker and it will create more friction on the blockers.
 
tranny

Well I liftet up the back wheels and started the car and had her in first and the wheels didn't seem to spin. I went through the gears and it went all the way from first to fith much better while the wheels were spinning. When I would hit the brakes and stop the wheels and try and get it in first it would hang up and then go in.

two things I am thinking.

1. Me using ATF without the friction modifier in it and it causing the sycrosnizer blocker to to really stick not letting the hub mesh with the gear.

2. when I rebuilt the tranny I should of replaced the syncronizer sleeves or hubs but the guy from Southern Gear said they should never need replaced. The syncronizer sleeve or hub's teeth were a little rounded and not pointy like when they are new but I know that the sycronizer hub for fourth gear the teeth still had a pretty good point for easier shifting so that gear should shift stopped or not but had the same problem as the others.

This is with the rear of the car off the ground for wheel spin

This is so weird because if the car is shut off it will run through the gears ok but if it is started and the clutch is in it will not let me run through the gears even if I push the clutch in and try to put it in gear and let it out and push it in again. No go will not go in gear with out effort. That would make we think the input shaft is still spinning but if it is in gear then the tires should spin. If I let the clutch out while in first or any gear the tire will start spinning and when I push the clutch in the tires completly stop spinning.

I will mess arround with fluid and see what happens with friction modifier.

Thanks guys
 
Think a little harder about what is going on in the transmission, you are on the right track though.

With the engine running and transmission in neutral. Input shaft is spinning at engine speed. Under normal conditions, when you put your foot on the clutch, the drag of the gears will slow down and eventually stop the input shaft from spinning. If you attempt to put the car into a gear with the input shaft still spinning the syncro will create additional friction and stop the input shaft from spinning. This phenomenon will result in an initial resistance to going into gear and as the syncro overcomes the inertia of the input shaft it will allow the gear to go in. If on the other hand, something is keeping the input shaft spinning then the syncro not only has to overcome the inertia of the shafts but also whatever is dragging. This could be a pilot bearing or a slightly dragging clutch. It doesn't take much on an 11" clutch disc to overpower the tiny syncro's friction surface.

This is why I suggested putting the car in the air. If you have the car running in neutral and you try to put the car into 1st gear (with the clutch in of course) and the tires attempt to turn, then you have a dragging input shaft and/or clutch. Just to make sure, hold the clutch in for several seconds before engaging first gear (this will make sure the input shaft has enough time to stop turning if it is going to be inclined to do so.

If you don't feel that a dragging input shaft is the problem, then I suggest that you add friction modifier and go out and drive the car a little and see if it quickly improves. It won't work imediately because the fluid (friction modifier) has to have some time to mix and work it's way into all the syncro surfaces. It should work within a 1/2 hr of normal around town driving going "nicely" through the gears.

Generally the blocker rings themselves don't show any wear on rebuild. Usually I only see visible wear on the reverse blocker. I've seen some so bad that they have no points left at all and in fact I had one so bad it got stuck and wouldn't slide. I was able to "repair" it with a die grinder. I did not attempt to rebuild the ramps, I just used the die grinder to take away the "folded over" metal on the teeth so it would slide freely again. So ya, if the teeth aren't really nice anymore you may have problems that nothing else will fix but it would have to be pretty bad IMO.

I say put the modifier in it and go drive it around a little.
 
M5r2

Dave have you ever bought any 1-2 or 3-4 slider blocker rings? I mean can you get them. I want to try and do another tranny I have and want to replace them. If not then I will have to find a tranny that works and hopefully get some good blocker rings from that.

I seriously thought about grinding the teeth to more of an angle and now kind of wishing I did because the ramps were rounded on 1,2, and 3. the rest still had pretty good points.

Well after buying two bottles of GM syncrose mesh that's all I could get right now. I put in two bottles of GM syncrose mesh and one bottle of synthetic ATF and one bottle of friction modifier. It seems to be shifting a little better but I havn't had time to get her one the road. I will do that this week.

Thanks alot for the info.

hepcat
 
I have not bought new ones but you can order them from Mazda for $150 or so each. It is cheaper to find another transmission as they usually dont' show any wear unless the previous driver insisted on either powershifting or kept forcing the gears after the syncro's were shot.
 
I had the M5R2 in my '89 SC completely rebuilt about a year ago. I remember it feeling pretty stiff whe I first got it. Come to think of it, it is still fairly stiff compared to the T-5 in my mustang. I have also had the experience that the transmission is very hard to shift when the car is not moving. It is my impression that these transmissions just do not lend themselves to quick shifts. Remember that, in 1989, ford had very few transmissions on the shelf that would handle the SC's torque. Consequently, they had to resort to a transmission that is essentially a truck transmission.
 
Well..one thing you can rely on...especially with the continued interest in the SC (hell, we have whipple and turbo options in the very near future).......is that there will be T56 kit eventually. However, be prepared to shell out a few grand. It will be worth every penny though!

Micah
 
Since rebuilding my M5R2 I too have a slow shifting problem. Not related to clutch problems. I have had two clutches in the car and same issue. My trans shifts just fine below say 3k rpm's but above 3k it gets slower (harder) to shift. My belief is the blocking ring is not able to spin the next gear up fast enough to let the shift fork engage the next gear without having to wait 2-3 seconds. Speed shifting below 3k produces grinding and above 3k is impossible. The engine revs to 6k and I have to let the rpm's drop below 4k before it will shift. I am using Royal Purple Synchomesh in the trans. I am going to add a bottle of Ford Friction Modifier to help increase the friction between the blocking rings and the hubs. The friction modifier works on both fiber and brass blocking rings.

Rich



M5R2 Rebuild How-to
 
Rich Thomson said:
Since rebuilding my M5R2 I too have a slow shifting problem. Not related to clutch problems. I have had two clutches in the car and same issue. My trans shifts just fine below say 3k rpm's but above 3k it gets slower (harder) to shift. My belief is the blocking ring is not able to spin the next gear up fast enough to let the shift fork engage the next gear without having to wait 2-3 seconds. Speed shifting below 3k produces grinding and above 3k is impossible. The engine revs to 6k and I have to let the rpm's drop below 4k before it will shift. I am using Royal Purple Synchomesh in the trans. I am going to add a bottle of Ford Friction Modifier to help increase the friction between the blocking rings and the hubs. The friction modifier works on both fiber and brass blocking rings.

Rich
Rich, friction modifier decreases the coefficient of friction, it does not increase it. High quality synchromesh fluid often has friction increasing properties to assist brass blockers generate enough friction to enable them to do their job. Friction modifier is used to make the fluid more slippery so that the fibre blockers do not engage as abruptly.

Fibre lined blockers have the opposite problem as solid brass ones. They grab so well that they will hold the gear too tightly to allow the slight movement necessary once the gears are speed matched to let them slide together.

Sorry the explanation is in my words and not out of a book so I hope I didn't confuse anyone. However, the bottom line is that you will need to add at least the recommended amount of friction modifier, possibly more, to make it shift right.
 
m5r2

This is one thing I beleave is slowing m5r2 after rebuild. Before our trannys gets taken out and rebuilt how much grinding happed and for how long!

With this happening what ever gear that is grinding. That gears splins that are supposed to be sharp are now dull that the hub slides on as well as the hubs splines that used to have a sharp point. The hub is what slides and enjages first or second or third or four and a seperate one for fith.

Another thought I had was since this is a truck tranny and is heavy duty is has to be alot heavier (I mean the internal spinning parts) than compared to the t5 that shifts quicker.

It took my tranny 3 months before it started shifting well with the friction modifier and gm syncromesh and even better after sitting for 4 months. I don't get it but time seemed to help and no grinding now but still have have to wait 1 second before it goes into gear and better as the rpm's go up.

Hope this might help with a possible reason why.
hepcat75
 
Back
Top