My first post obviously. Amazing how many Ford truck sites there are.

My 02 F-150 4.6L/5speed 4x4, was bought new and has been a good truck. A couple years ago I noticed on a long drive at interstate speeds that when I downshifted or upshifted into 3rd that it would refuse to go in gear without letting RPM's come down. It has progessed to the point that yesterday was hot and grinded every time I hit 3rd. Pull over let it cool off no problem. Cold outside no problem. Drive for an extended period at speed (20+ minutes) or hot outside - grinds. No other gears do it, and as a Mustang owner too, I know 3rd is the one you tear up in those too - usually a bent shift fork. But once bent it is always bent, not like this which is obviously heat related.

Anyone seen this before? 3rd gear shift fork or syncho?

Also I have changed the fluid twice (syn) with no avail. Some told me heavier oil - no sure about that one. Right now its IV Mercon ATF is memory serves.

 

Welcome to our world......It sounds like you have a syncro going out.My last experience with a standard tranny was on a 93 Eagle Talon Turbo TSI with a 5 speed.It was recomended that I change out the tranny fluid to BG Syncroshift. I did,and the problem persisted,but was less apparent.It was ALSO suggested that the shift linkage itself could be the culprit.I sold the car before I had the chance to prove/disprove that theory,but the guy that bought the car said he knew what the problem was(Linkage) and had ordered the parts to fix it.This was AFTER he gave me the cash and got the Title
Since you stated that temperature seems to be a factor,I doubt that the linkage theory is the problem...hope this helps.
Again,welcome to the forum.You will find as time goes on,and you participate,that there are alot of people here that know their stuff,are willing to help,and friendly.

 

I have the same truck/tranny as you do. The tranny has shifted poorly since day one. It would grind especially in the warm weather or when the tranny heated up. If you are using ATF fluid that could be your problem. It was part of my problem. I finally switched to a synthetic syncromesh manual tranny fluid. It helped a lot! Now in hot weather and when the tranny heats up it doesn't grind. The shifting is still extremely notchy however. The synthetic syncromesh fluid is about the same viscosity as ATF, so in the winter when first starting out cold the shifting is ok, it's not stiff. Also the syncromesh fluid has additives that are better suited to protect your tranny than ATF's.

Whimsey

 

I want to congratulate you guys on being the first two people to offer anything constructive about this problem. I have posted this on countless forums like 10 - 15 over the last year and gotten basically 0 replies. So whimsey are you referring to Amsoil synchomesh or is that just a generic name? Sorry I am not familiar. I don't appear to have a dealer around me, just a bunch of guys with residential addresses in questionable parts of town.

ATF fluid was right out of my owners manual so that would annoy me if Ford is wrong.

As for the shift linkage, my wife has contended that the gear "moves" but to me it is not the problem. If the linkage is bad in some way, how do you find it beyond the obvious major bend in it? Which way gets a better look at it, up from underneath or down thru the transmisson tunnel. Never taken that shift boot off on this vehicle.

 

Im not completely familiar with Ford linkages,but would suspect that they all are basically the same. I would pull the boot,and look for any "slack" in the mechanical action...especially where the linkage connects.
From my limited experience(not on Fords specifaically) slack will usually be found at the linkage end points such as a spot where a rod attaches to a metal lever.These spots get worn a little every time the shift function is done,and can easily become "egg shaped'. This causes slack in the linkage. There could also be bushings at these points that can wear.
The Tranny fluid I mentioned is made by a company called "BG". if you want to find out more about it,just "Google" BG SYNCROSHIFT....

 

Thanks for the clarification.

My local Ford dealer, 4 blocks down the street, is listed as the dealer and they have one kit. And DAMN it's sold 3 32oz bottles for $96.98!! Is that right or do I need to find another dealer?

 

The shift linkages on your transmission are internal to the transmission. There is nothing to be seen on the outside so any "slack" in the shift lever is on the inside of the transmission. Dan.

 

Glad you corrected my post,wasnt at all sure about the situation,as I have never seen a Ford Standard tranny workings.

Thanks again...Alan

 

I have the exact same truck, and I had an issue with it as well. Turns out, it may be shift technique. I can avoid grinding third by running the r's up to 3100 in 2nd. I know this, because i paid $2300 on a rebuild on my M50D2, and it didn't make much difference. I add a bottle of Lucas every change, and it helped immensly. I would avoid a rebuild unless it's very hard to shift to third. Thats the difference between $13 and $2300. Just my two pennies.

 

I was referring to "generic" syncromesh type manual tranny fluid. Amsoil makes one as does Royal Purple, which I'm using now. There are other syncromesh manual tranny fluids from other companies, some are synthetic others are not. Next I'm going to try a slightly thicker synthetic manual tranny fluid and see if it helps with the notchy shifting and still flows ok in the NJ winters.

I ordered my syncromesh fluid through the internet. It was easy, fast and inexpensive. Check your local auto parts stores and speed shops. I also believe that GM dealers sells a synchromesh tranny fluid. But I would suspect that it's expensive, as most dealer fluids are.

Whimsey

 

Alan, You are welcome. I'm happy to offer what little knowledge I possess. LOL. Dan.

 

My 2000 F150 4.2 5 speed has a sort of squeal or sqweak when i try to hit 3rd sometimes. Would this be the same problem early in the making?

 

Honestly I had no problem until making a non-stop 11 hr drive. Slowed down to make a quit pitstop and couldn't figure out how I missed a shift.

 

I found this in the archives:

Consumer Info

M50D, is that the right transmission for this powertrain?

02 4.6L 5-speed.

 

Well I don't see what they are talking about or my truck isn't leaking in this area. Needed to report I tried the Royal Purple Syncomeshmax fluid and things are the same.

I have had some other recommendations - tell me what you think:
1. Change to 75w-90 gear oil
2. Overfill the transmission

Once again as long at the fluid/transmission is cool, no grinding, so it is without a doubt a temperature issue.