# Ford 3910 PTO Problem



## pledbetter (Aug 15, 2011)

This tractor was used with brush for a paving company. The PTO in the back will not engage. It did once for about 10 minutes then quit. Any suggestions on what we can do to get it working? We did change the hydrolic fluid..
The lift is working just fine but the PTO does not engage.


----------



## sixbales (May 18, 2011)

You need to get a service manual for your tractor - ebay has many listed.

Tractordata.com states that your 3910 has an independent PTO, but I also have seen a listing for a double clutch and live PTO for a 3910 in a parts catalog on the internet. My guess is that you have an independent PTO, but the first step is to determine which you have. 

If you have a live PTO (two stage clutch), the PTO shifter shaft is supported by and run through an inspection cover on the left hand side of the rear axle center section. 

If you have an independent PTO (except those with Selecto-Speed transmission), the PTO shifter shaft is supported by a machined bore directly through the rear axle center section housing itself, above the left hand inspection cover. 

Please post back which you have.

For troubleshooting an independent PTO, the following is listed in my manual for PTO not engaging or slipping under load: 

A. Low rear axle oil level. Have you filled the rear end to the proper level? There is a fluid level check plug (square-headed 3/8" pipe plug) behind your right heel as you are sitting on the tractor. Fill the rear end till fluid flows out this port. 

B. Failure of hydraulic pump (you stated that your lift works ok, but is it slow?).

C. Failure of connecting pipe. 

D. Control valve stuck open.

E. Control valve spring broken.

F. Cast iron sealing rings on clutch broken.

G. Clutch piston sealing rings leaking. 

H. Brake piston sealing rings leaking.


----------



## pledbetter (Aug 15, 2011)

There is no 3/8 plug on the rear end part of the tractor housing. We know it was one of the first ones made mid 80's tractor. There is what looks like a plug but it's an allen wrench type. 

It is an Independent PTO. What is strange is we changed the fluid, and filter and it started working after about 10 seconds of running.  Then stopped in the field for a few minutes and when I started again, it would not engage for about 5 minutes then it started again but stopped a few minutes later. Not really even under a load.


----------



## sixbales (May 18, 2011)

Try this link to spot the location of the fluid level check plug

http://[URL="http://agriculture.newholland.com/us.../homepage.aspx"]
agriculture.newholland.com/us.../homepage.aspx[/URL]

click on parts and service
find parts 
model 3910
rear axle
rear axle center housing
See item 14 on the diagram. SQUARE HEADED PLUG. It appears that they went to a bigger plug in 1981 (see item 15).

The diagram also shows the dipstick and tube for checking the rear axle and hydraulic oil level if your tractor has a CAB. Does your tractor have a cab?? If so you have a dipstick to check the rear differential fluid.

The square headed plug is on the right side near the flow control valve. 

I've read that a 3910 rear holds 48 quarts of fluid (12 gallons).


----------

