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Pete, Automotive Mechanic
Category: Transmissions
Satisfied Customers: 27814
Experience:  GM and Mercedes vehicle technician.17 years experience.
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1999 ford v10 4R100 2wd.shifting hard.when I take off on

Customer Question

1999 ford v10 4R100 2wd.shifting hard.when I take off on first start it shifs great like new . if I have to stop for a lite and idle anddont matter what gear it idles in .when I take off it shifts in so hard the fan belt squeels then shut it off and restart engine take off and shifts great till I stop and idle again and shifts hard again. I changed fluid and filter pan was very clean.not much on pan magnett
JA: What shape is the fan belt in? Do you know if it needs to be replaced, or just adjusted?
Customer: surphintean belt is new last season its a class A motor home
JA: What is the model of your '99 transmissions?
Customer: 4R100 2wd
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: I try to but took this to the dealer .they changed the speed sensor in tail shaft
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 1 month ago.
Category: Transmissions
Expert:  Pete replied 1 month ago.

Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.

Debris build up in the transmission valve body can be a common cause for this fault here.I have had to perform a transmission fluid flush to remove any debris and dirty fluid and install new fluid at the same time with a flush machine.

I have also seen where the pressure control/regulating solenoid can act up in the valve body in the transmission as well as the valve body itself needing replaced.

If you have not had a flush done I would try this first.If this does not work then I would have the valve body tested to see if it needs replaced or rebuilt to resolve this issue.Usually since you can cycle off and on the engine and it works properly for a short time it is an electrical fault and the pressure control solenoid can be most common needing replaced.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service,your 5 star rating is appreciated.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete