RP's Synchromax didn't hold up

[tdi-rick]

30,000 miles is a long way, what is the fluid capacity of the 'box ?
I'm not a fan of extended mileage with manual gearbox fluid's regardless of fluid used as often there is minimal fluid volume, they run in a very hot environment, contaminants from the synchros load up fairly quickly and even premium fluids tend to shear, or at least beat the FM's to death.

I've had premium ester/PAO formulations develop baulky/crook shifting in 25,000km/12,000 miles in one application as it only holds 2.3 litres and is behind a turbo diesel hauling a big, heavy 2600kg 4WD.

 

[STG]

Doesn't Ford call for Mercon V ATF in the 2006 Ranger?

Maybe the OP should have tried Royal Purple ATF.

RP ATF is fine in my 2004 Mach 5 Speed. It's Tremec 3650 (Ford specifies ATF) is notorious for notchy shifting and RP ATF works fine.

 

[1kickbuttranger]

I had switched the manual transmission fluid in my ranger to M1 ATF @ 70K. This was the first time I had changed out the fluid. It felt ok, but got worse at about 90K...
Then I decided to check it and it was nealry black/purple color and smelled badly burned. I immediatly changed it out to chevron ATF (Dexron3) and it was much better. It does still seem like it takes its toll on the fluid, so I end up changing it every 3 oil changes. 196K on it now and doing well.

 

[wander2039]

Capacity is just a little under 3 quarts and it calls for Mercon. Can't recall the recommended interval if there is even one. Starting to wonder if Mercon V isn't going to work either. When I shift it seems like I have to hold it against a gear for a second before it'll even let me shift into it. Could it be to thin for the synchro's?

 

[wander2039]

Can't say the MaxGear 75w90 turned out any better. Didn't thin down as much. The factory gear lube in my 00 F150 looked better at 75k than this did at 36k. Pumped out a quart and replaced with dino 80w90 may do a full dump in 15-20k.

 

[Tremo]

My old 88 IROC (WC T5) has 50/50 mix of Synchromax and M1 ATF, and it shifts great. That stuff has been in there 3 years now.

 

[wander2039]

I would say it's the M1 helping. Have had M1 in the Escape for 20k and it came out looking like new.