I'm new to FTE, but impressed with the quality of this site! I have an '87 F150 with a 4.9L and 4 speed. After things warm up I get a lot of gear grind when going from neutral to 2nd, like when starting from a stop light. (1st gear is a granny). My first take was that the pressure plate was not not being depressed enough to release the clutch disc completely, resulting in the gear grind, but after looking around at the clutch mechanism (hydraulic master cylinder to slave cylinder on outside of trans.), nothing jumps out and says "adjust here". I've been called dumb before so go ahead and point out the obvious!

 

There's no adjustment on the hydraulic clutches, so you're right about that.

One common cause is firewall flex. The firewall where the clutch bolts to has a tendency to weaken and flex when you push the clutch in. That will lead to partial clutch engagement, even if the pedal is on the floor.

You also might want to bleed the system, it takes regular brake fluid.

Also change the fluid in the tranny, it takes 80w90 gear oil.

 

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Andym: Thanks for the response. Give me a day or so and I will try the things you suggested and will report back. Junior Barnes.

 

No problem changing the trans. oil... it's a "normal" trans. Then I went to bleed the clutch hydraulic master/slave system as suggested....so I began talking to myself, asking where the little bleeder valve is located? The only thing close to one is that silly little allen head screw/plug. Back to FTE for a search on the subject. The gravity bleed method appears to be the method of choice,(there doesn't appear to be much of any other choice!) but it also appears that success can be elusive for some. So do I get it that the gravity system process is to remove the allen screw, pump the clutch pedal and fill the reservoir accordingly, all the while (brake) fluid is oozing out the open hole? Then when certain all the air is out of the system, replace the allen screw.You mean, no bleed valve, and no hose (with its end submerged to prevent air contamination) like when one bleeds brakes? I would have gladly paid for a bleed valve to avoid the hassle and mess! The other thing that doesn't help the gear grind is the high idle the truck has....even after warm up. I've been told by Ford that the idle is all set electronically and there is nothing I can do about it. Jabbing the gas pedal seems to bring the idle down to a more respectable level, lessening the gear grind. Right about now I am missing my old '91 1 ton/460, whose engine went 300k. Wish I could say the trans. with the manual lockout O.D. went that far too....I was on my third trans. when the engine died! This '87 F150 with the 4.9L and 4 spd. is for my son who just got his driver's license! Any wheels are looking really good in his eyes!

 

Bleeding the clutch is a 2 man job. The bleeder is located just above where the line go into the bellhousing. You need (I think) a 7/16" wrench to loosen it.

Anyways, one guy climbs under the truck and opens the valve while the other guy (gently) depresses the pedal. Then close the bleeder and raise the pedal. After it looks like you have all the air out I usually get the helper to stand on the pedal and then I crack the bleeder again, just to get any remaining air out.

And the tranny uses ATF. I replaced mine with Redline MTL and it seemed to help the shifting somewhat. I've only had it in for a couple of weeks though and I've heard it takes a while to get the full effect.

 

My slave cylinder is external and there is definitely no bleeder valve on it...just the line coming down from the clutch master cylinder and the allen head screw/plug on top of the slave cylinder. I have always had to get someone's help when bleeding things (e.g. brakes) in the past, having never had the luxury of owning or using one of those one person bleeding pump/systems. Are you saying to put ATF in my 4spd (granny 1st) manual trans.?Am I so old school to believe that 90wt. gear oil in these trannys is a thing of the past? A guy stopped me outside an auto parts store recently while I was driving my '66 VW and told me he was putting synthetic oil in his transaxle and it made a huge difference.I guess I was having a senior moment at the time because I can't remember the weight of oil he recommended!

 

I missed the "4 speed" part of your post and thought you had a 5 speed...

I never did have to bleed the slave in my old truck so I can't offer any advice there, but the Red Line MTL is supposed to be 70W80. They also have MTL 90 which is 80W90.