MT Fluid for problem Ford (ATF spec)

Joined
Oct 12, 2010
Messages
857
Location
GA
5-speed manual in a late 90's Ford Explorer. Spec'ed fluid is ATF. Did a drain fill with Maxlife and it's OK but a couple synchros are clearly worn.

In a Toyota trans I'd try adding some Redline Shockproof but I'm not sure what magic friction modifiers would be best to try in this case. GM synchromesh? A Lubegard product?

Or forget it all together and just rebuild the trans like a reasonable person?

Thanks for the ideas!
 
Joined
Mar 20, 2008
Messages
14,136
Location
USA
No fluid can fix a bad transmission, manual or automatic. Was it acting up before the fluid change? And what fluid was in there before? :unsure:

You might want to try a Synchromesh fluid like Pennzoil or Valvoline Synchromesh. There is also Royal Purple Synchromax.
 

JZiggy

Thread starter
Joined
Oct 12, 2010
Messages
857
Location
GA
No fluid can fix a bad transmission, manual or automatic. Was it acting up before the fluid change? And what fluid was in there before? :unsure:

You might want to try a Synchromesh fluid like Pennzoil or Valvoline Synchromesh. There is also Royal Purple Synchromax.

Yep, agreed.

Fairly clean ATF, unknown brand was in there before. Was acting up before the change as well.

No worries about viscosity differences between a lightweight synchromesh and ATF? I guess maybe they aren't that different?
 
Joined
Jan 24, 2013
Messages
1,133
Location
Upstate NY
I owned an '87 Cherokee Sport with the AX-15, and 200k on the factory fill. (purchased off friend who was original buyer). Trans became very hard to get into gear, especially when cold. The brass synchronizers were worn I suspected. I joined an XJ forum and read tons of threads about the transmission fluids and decided on the specified 75W-90 synthetic GL-4 oil. The fluid GL-5 supposedly was a no go in them, supposedly the friction modifiers were bad on the synchro's. The fluid didn't do anything for the forces shifting into gear, or cold performance.
I did much more research on the forums, and some were using motor oil in with positive effects. 10W-30, 40, and 50W oil. I filled it with 10w-40 synthetic and it was much better in every respect. Shifts required less force into gears, cold weather operation was very much improved, and I was shocked that it had that much effect on it.

The transmission lasted another 100k with rough use, towing heavy boats, car trailers, and some off road use also.

I'm not saying that fluid will "fix" a transmission that needs a rebuild. But in my case the fluid change decreased the forces needed to shift into gear. I still can't understand why the fluid had that effect on the synchro's, but apparently helped in my case.

Another fun fact, the jeep had its original clutch too, still performed well without any issues at all. Now, the hydraulics for the clutch on the other hand, thats a sore subject..
 
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