92 manual trans issue

[yosh18981898]

So the other day I jump in my x to head to town and all of a sudden the transmission was grinding every time I downshifted from 5th to 4th. It would grind as I was going into 4th. Every other shift, including 3-4, 4-3, 4-5, and 5-3, is smooth as silk and the transmission makes no unusual noises. It did this on every 5-4 shift for that trip. At the end of the trip I sat in my driveway, with the engine running and clutch in, and shifted 4-5 and 5-4 repeatedly. Since then, the 5-4 shift is just as smooth as ever, not grinding at all.

I like to fix issues before they become real problems, and in this case, at 113,000, my tranny is just too young to die. Because of the nature of the problem, I'm thinking it has to be a syncro (although I've never been inside a manual trans, so don't hesitate to correct me). My first action will be to drain the trans fluid and refill it. I'm thinking since the fluid in there is 13 years old, there could be gummy fluid and metal shavings that are getting the syncro stuck and keeping the gears from alligning as they should. (Again, if this doesn't make sense, then tell me! )

I want to put synthetic fluid in there next time. Does anyone have recomendations? Also, I was planning on removing the shifter and floor access panel to gain access to the fill plug, will this work? Also, while I'm in there, I may as well replace those rubber shift rail plugs with the metal one's I've heard guys raving about. I need information on where to get them.

Thanks guys!

 

[TheFox88]

As far as I know you can get those plugs at any auto parts store. Look for BMXKing's thread on what fluid in the 5spd, the part numbers are in there. As for fluid, any ATF will work as far as i know. Mercon (sp?) is what Ford recommends. I plan on getting some full synthetic amsoil from the dealer on this board and replacing it when i get those plugs and my new Hurst Shifter sometime next week.

 

[yosh18981898]

Anyone have any ideas on the grinding when going into 4th from 5th?

 

[bmxking5]

Yeah, you can get them at Napa. Advance Auto Parts didn't have them. The part numbers are in that thread Fox is talking about. I don't really know about the grinding from 5th to 4th. We tried to put in the metal freeze plugs to replace the rubber ones through the inside, but because of the extreme lack of room (Easier with a BL...which I don't have) we couldn't even hammer them in straight. One popped into the trans and when we were trying to hammer them in, the freeze plugs were "chipping" some of the metal on the trans, which was starting to go into the trans. We put in the rubgber ones again, RTV'ed them. Anyways, we drained the fluid, got out the freeze plug with a magnetic flexible hose thing (it was at the bottom but didn't come out) and then filled it with some Hurst ATF stuff that said it met/exceeded the Dexron/Mercon stuff. It now shifts better and has absolutely ZERO leaks! Finally I'm almost happy with this transmission.

 

[alexefron]

Sounds like a syncro, however im not sure why it would only be doing it on the downshift.

 

[yosh18981898]

Is a syncro something I can replace myself (I guess I could even take the tranny out if I had to) or is that way inside the guts of the tranny and better left to a transmission rebuilder?

 

[Timoteo]

I had a 92 manual as well, sold it 2 months ago after I bought an 02. My 92 had occasional problems with 3rd gear shifts. I would advise you to check your clutch operation (fluid levels) also if you haven't changed your tranny fluid now would be a good time. I had good luck with Mobil 1 Syn ATF. It may be the syncro, which would require a tranny tear down to replace. My suggestion is be patient when shifting, foot off gas, depress clutch, smooth gear change (not quick), a little gas (on downshifts), release clutch. Your vehicle will last much longer. Mine had 175k when I sold it.

Tim

 

[yosh18981898]

Well, I changed the tranny fluid on thursday. I put some AAMCO brand synthetic blend Mercon V ATF in it. All the shifts are now extremely smooth but it still ground two or three times going into 4th from 5th in the 200 miles I've put on it since changing the fluid.

If it is a syncro, why does it only grind on the 5-4 downshift, and not any other shifts? Any body got any other ideas?

 

[Timoteo]

There is a syncro for each gear. That syncro is likely worn, stuck or has other damaged. The job of the syncro is to syncronize the speeds of gears and related shafts so they are turning at the same speeds and can"mesh" together. If the syncro is worn or not functioning properly you'll hear grinding. Syncro's are wear items, they act like friction clutches to do there job. Make sure your clutch is fully releasing, shift slower (or wait a bit longer) after you push in the clutch,

Tim

 

[rockstar]

My tranny (91 XLT) started grinding when going into 4th gear also. Doesn't matter if it's a shift from 3rd or 5th. Also, it doesn't happen until it warms up. This is just after having a new clutch installed. I'm now getting a remanufactured transmission installed. Hopefully I'll be good to go for a while now.

 

[yosh18981898]

Well after I changed the tranny fluid, it continued randomly grinding on the 5-4 downshift and then on 4-3 downshift just a couple times. Then it stopped and has been shifting perfectly smooth as silk on every shift for the last 5000 miles. I love it when problems fix themselves

 

[briwayjones]

Double clutch when downshifting.