The left front axle on my F-250 has recently been engaging on its own occasionally. The precipitating factors are always the same; hitting the brakes with a moderately rapid deceleration while turning left. As my speed gets to about 5MPH, it will feel like the truck is on ice on the L side as the truck seems to slip a foot or so forward during the turn. It is not on ice and not slipping.
After this sensation I can tell the front axle is engaged as I speed back up and hear the hum. When I stop and go into reverse, I can disengage the axle and all is back to normal.
The truck is a 1997 F-250 without manually locking hubs. 250K plus mile and other than that going strong. As I said, the problem is only intermittent and the only common threads are this turning deceleration. I would appreciate any help.

Thanks,
Pete

 

defective automatic hub. put a set of manual hubs on and it will solve all your problems.

 

Unfortunatley there isn't much fixing to be done with the auto hubs themselves. The best repair is a set of manuals.
However, it might be worthwhile to pull the hub and spindle and check the bearing in the backside of the spindle that the axle rides in, when they go bad they can cause manual hubs to lock in on their own, so I could see it causing issues with an auto as well.

 

Thanks for the advice and info. Seems like a combination of left and forward inertia is the cause. Is changing to manual locking hubs difficult?

Thanks again

 

not really. just remove the auto hubs, cap off the vacuum lines, and install the new hubs.
just make sure you get ones to convert from auto to manual.

 

No vacuum lines on a 97.
Depending on which bearing retaining nuts you have you may need to change them. If you have a large hex spindle nut you will need to get a new set of manual hub style ones that use the 4 pin socket.

 

Depends on which '97 F-250 he has. If it's the light duty (looks like a '97 F-150) it probably does have a vacuum line. If it's a heavy duty (looks like the '92-'96 F-series and the '97 F-350) then it does not.

 

My assumption is a real F250, not a 7 lug F150, as they run a center axle disconnect, not locking hubs.

 

TJC, 82F100SWB and Nothing Special. Thanks so much for all the great info. Also found some great info on changing to manual on other FTE threads.
I really appreciate the help.

 

By the Way, no vacuum lines.