No engine braking

[Franco]

Pals,

Sorry if this is an old question, and I could not find it on this forum.

I have a 2000 4X4 XLT Ranger, with a 4.0 liter engine, and a 5 speed automatic transmission. I bought it used with about 125,000 miles, and it now has about 150,000 miles. I use it for road trips in the mountains, carrying a small Four Wheel Camper, which weighs about 1000 pounds loaded.

The truck performs very well, both on and off pavement, except for one problem. In critical situations, the engine will not brake the vehicle. When that occurs, the transmission works fine when the vehicle is proceeding forward, but when I let up on the accelerator, it free-wheels. On a couple of critical occasions, this has required excessive use of the brakes, causing the brake fluid to boil, and ultimate brake failure. I need to get this fixed for safety reasons.

Has anyone heard of this problem? I have found a technical bulletin from Ford, which refers to possible lack of engine braking in Manual 1st. (TSB 03-22-10, published 11/30/03.) This deals with the transmission main control valve body separator plate. I am not sure if this relates to my problem, which can occur in all gears, including 4X4 high and low ranges.

Do I need to have the transmission rebuilt? Is there some lesser repair which might do the job? More importantly, is there a way to diagnose the problem? When I brought this to my transmission guy, he proceeded to lecture me on how bad an idea it is to use an automatic transmission to brake the engine. That's unrealistic thinking in my situation.

As always, any assistance will be GREATLY appreciated! Thanks in advance.

Happy trails,

Franco

 

[Captain Ledd]

I've never had any luck with engine braking in an automatic. Any amount of slowing I've always contributed to aerodynamic resistance, because once pointed slightly downhill it's always accelerated.

Thats just been my experience though.

 

[rurouni20xx]

the auto tranny is supposed to freewheel. the convertor only locks up when pulling at certain speeds. i had this problem on my 93 4wd 3.0 a4ld in the mountains in tennessee going from mountain city to bristol. the first time i went thru it i smoked the brakes and cracked the rotors. the second time (same brakes) i put it in drive to go uphill and down to 1st for downhill and hardly touched the brakes. basically i manually downshifted and let the engine/tranny do all the work. wish i fig that out b4 i had to change the rotors that xmas.