5 spd grinds in reverse w/new slave

[91NavSport]

Just replaced the clutch and slave cylinder because old clutch suddenly wore out. It had been grinding when shifting into reverse before the clutch wore out.

I have repeated bled the new slave, and it still grinds terribly when trying to shift into reverse. I can see through the little opening in the tranny housing near the slave cylinder that the slave is pressing the clutch housing springs inward about 1/2" when the clutch is pressed to the floor. The clutch action is firm, not spongey.

Help! Is the slave still not fully bled? Is there a trick I should be using to assure that is properly bled? Is this just happening because the clutch disk is new and will go away as soon as it is driven a few miles? Or will this new clutch disk just wear out in a few days?

 

[Blee1099]

Sounds like the clutch is not fully releasing. Inspect the clutch linkage, it may only need a simple adjustment.

 

[91NavSport]

OK. I'll check that. Just drove it around and everything feels fine other than kind of notchy to shift into first at a stop. The peddle pressure feels perfect - firm and even without any sponginess. But shifting into reverse with the engine on is not even an option still.

Any chance the freshly machined flywheel and pressure plate along with the new clutch disk needs some break in?

 

[rookieshooter]

I do not know about that model transmission, but I wonder if it could be a syncronizer issue. Generaly their made out of a softer material like brass. They help to mesh the sliding gear that slides over the stationary gears. If I remember they have a sharp edge on each gear tooth and when they dull it makes it harder to get in gear.

 

[91NavSport]

The tranny internals certainly have wear since the milage is 169,000. It does seem worse now than when we bought the truck about 1000 miles ago. The sudden death of the clutch makes me wonder if it is just my 21yo son (the owner), or was the old slave failing. Put in new slave with new clutch assembly and grind into reverse is as bad as ever.

Some suggest Mobil1 ATF. How much does that help syncro clash?

Does anyone suggest Redline MTL?. It works great in our Mitsu manual trannys.

Anyway, we had to put the Navajo back on the road tonight because it as a daily driver for work, so all advice is desparately needed! The rebuild took a stupid number of hours, so please help me from having to repeat the hell job (and lost time from work)that pulling the tranny is on this truck!

 

[rookieshooter]

Just happen to be going thru the Altas transfer catalog when I noticed this pic of a slider gear. You can see the sharp points at the end of each tooth. They inturn slide over the syncronizer ring gear that has the same type teeth but on the outside. This is what I was talking about in my first post.The syn. gear if I remember spins freely on the same shaft as the reverse gear, It is between the slider and all gears. As the name implies helps to syc. the slider gear which has the shifting fork over it to slide over and engage the reverse gear. When these points start becoming rounded they can cause a shifting problem. This might be your problem.

 

[91NavSport]

Thanks for the information, Rookieshooter. If that's the case, I guess my son will have to shift into reverse with the engine off for the forseeable future...

 

[Creager]

you know what, Mine always did this after i replaced the clutch and slave cylinder at a shop (when i didnt do it myself)

it would only be a problem for like a week, it always seemed to do this...

 

[91NavSport]

Thanks Ceager. My long shot hope is that this is temporarily related to the new clutch (at least the extent that it grinds right now). If it improves, I will post back.

Blee1099 suggested that i adjust the clutch linkage, but my Chilton's (I know it's pretty crappy) states that the hydraulic clutch system provides automatic adjustment and that no adjusment of linkage or pedal position is necessary. Is there adjustment that can be done to increase stroke that can reduce the grind into reverse?

And again, has anyone noted the correct travel range for the slave cylinder? I saw it push the pressure plate springs in about 1/2 inch.

 

[rookieshooter]

This if for an Ex but it should be the same procedure I would think. See para. 10

 

[bills]

does that mean you should pump the pedal like 50 times!?!

 

[rookieshooter]

No each cycle is hold for 1 to 2 seconds and release = 10 pedals

 

[ejbeach]

Had this problem with ranger

I went through this with my 97 Ranger. Its true there is no adjustment with the hydraulic system. I used to pump the hell out of the clutch pedal then it would fix it for a while.

It's definately not a transmission problem, because reverse is a non synchronized gear. When you are at a dead stop you should be able to shift into any gear without grinding.

The grinding is cause by the pressure plate not releasing the clutch all the way, leaving the clutch partially engaged.

Be cautious, when you are sitting in traffic with the clutch in and the vehicle in gear, it will start wearing the clutch plate because of the partial engagement.

Ford replaced the clutch, press. plate, and slave 6 times over a 5 year span, and it was never totally right. It still had problems when i traded it in.

Good luck

 

[rookieshooter]

I went through this with my 97 Ranger. Its true there is no adjustment with the hydraulic system. I used to pump the hell out of the clutch pedal then it would fix it for a while.

It's definately not a transmission problem, because reverse is a non synchronized gear. When you are at a dead stop you should be able to shift into any gear without grinding.

The grinding is cause by the pressure plate not releasing the clutch all the way, leaving the clutch partially engaged.

Be cautious, when you are sitting in traffic with the clutch in and the vehicle in gear, it will start wearing the clutch plate because of the partial engagement.

Ford replaced the clutch, press. plate, and slave 6 times over a 5 year span, and it was never totally right. It still had problems when i traded it in.

Good luck

Granted It sounds like he may have not bled the air out of the lines/per instructions. But you can not say it rules out the transmission. The slider gear that I posted a pic of, have those sharp points on the teeth. They are not there for nothing. What they do is to find the space between the teeth on any gear including reverse and make it so it can slip between the teeth. So now that even puts more pressure on the slider gear to mesh with the reverse gear being that this make tranny has no syn. in reverse. If those teeth get dull, it dosen't matter how far that clutch disengages the disc from the flywheel it will grind.

 

[91NavSport]

Rookieshooter: I followed the procedure and repeated it for literally two hours. I could see through the opening in the tranny that the slave was pushing in the pressure plate springs by at least a half inch and it did not relax when the clutch lever was held down, even for minutes. So either that distance of slave travel is insufficient or maybe there is STILL air in it after all the bleeding I did. What the heck, it can't hurt to bleed it again...

I sure wish somebody could tell me what the slave travel should be.

ejbeach: I told my son to make sure that he puts it into neutral and lets out the clutch when stopped at a light (and not to hold in the clutch pedal for any extended period) since the clutch may not be fully releasing. This is frustrating, especially because the clutch replacement process is stupidly time consuming for this vehicle compared to others I have done. I am very worried about premature wearout of the clutch disk...

 

[rookieshooter]

This is a wild hunch. #1 Have you checked the fluid level in the tranny? #2 Lets say the slave is relasing the clutch properly. The disc has gears that mesh with the gears on the input shaft. ( this is generally how it works, so I'm assuming this) The input shaft slips into somekind of bearing at the end of the crank. Some of these bearings are made of brass. When I say bearing, the ones I have seen are no more then a piece of brass with a hole drilled into it to accept the round end piece of the input shaft. I'm thinking that if this does not spin freely when in nutral, that the spin of the flywheel that's connected to the crank could transfer spin to the input shaft because of gulling due to improper oiling or some kind of forgien matter between shaft and bearing not allowing it to spin freely ( Idealy when clutch pedal depressed input shat does not turn) when in nutral and making it hard to shift in reverse. Going back to #1 This actually happened to me about the oil in the tranny. We were reving up a race car on a trailer that was strapped down and in nutral. I did not know that one of the team members drained the oil the day before and forgot to fill it back in the tranny. Even though it was in nutral the gears shaft or something siezed up. All hell broke loose as this 700+HP started smoking the tires on the trailer. Just imagine what would have happened if this was in the pits!!! I know yours in not this low. but maybe just low enough so things could move that were not supposed to.

 

[91NavSport]

Latest Update:

My son said that it will now shift into reverse with NO grind (after 3 or 4 days of driving) and that all shifting feels normal now - at was also being very notchy going into first gear when stopped. This seems similar to Creager's experience.

Datapoints: The tranny was freshly filled with generic Mercon. I have not yet checked the clutch fluid reservoir level to see if it has dropped, which might indicate that the slave was not originally 100% filled with fluid and actuating the entire stroke. I'll post back if that is the case. Or could the cause simply be that the freshly machined flywheel and pressure plate surfaces needed to smooth out a bit to compltely release the new clutch disk friction material?

 

[91NavSport]

Checked clutch fluid reservoir level:

No change. I guess the parts just needed a few days of wear-in for the gring into reverse to go away...