greasemanicure
Well-Known Member
- Joined
- November 1, 2006
- Messages
- 168
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- City, State
- Burlington, NC
- Year, Model & Trim Level
- 1996 4X4 4R->5R mod
I spent the weekend under our 96Ex 4.0 OHV. A while back I started a thread about it losing reverse and going forward only if the OD was turned off. I also have a pressure gauge installed. Things did not go well and I'd appreciate some insight into what I might be overlooking.
The old valve body showed signs of gasket failure. There were cracks and it was generally brittle. There was nothing remarkable in the pan except the usual fines stuck to the magnet. Let it drip for days and cleaned off some stuck pieces of gasket material with acetone. While it was dripping I installed a drain plug in the pan. I used a replacement pan plug that has 1/2X20 threads and got a matching nut. Cut channels in three of the faces for drainage and welded it to the inside of the pan near the low area where the filter tub is. That will pay dividends. Also got a replacement low/reverse servo with the D-ring set. Also adjusted the bands along the way.
The new valve body came with a bonded gasket and some minor upgrades. It went in with no difficulty. I used an old valve body that I was given as a template to hold the screws as I did the removal. Given that I'm not that good at reading and tightening, I numbered the valve body screws with a paint pen in the torque sequence. Saved me a bunch of fussing when torquing the valve body screws. Did the tightening in three stages, ending at 97 inch pounds. I read enough threads that all reminded me to be sure to link the manual valve to the shift mechanism. Buttoned up the pan and filled it up initially with 6 quarts of Merc V. While the old low/reverse servo all but fell out when I loosened the bolts on the cover, the new one with the D-ring fit quite snug.
Started it up and the idle pressure came up to about 100PSI. Ran it through the gears, noticing that the pressure did the expected increase to 200 PSI in reverse. Also noticed the "clunk" of engagement and a drop in idle RPM. So far so good. Topped up the fluid with another quart, repeated the shifting and checked and added a little more. Here's where it goes to crap.
I put it in reverse to roll back off the ramps. No go. Seemed to pull OK in drive. Pushed it off the ramps and cleared the way, put it in drive and rolled off. About 50 feet down the driveway it seemed to go into neutral. Dragged it back with my F150 and started checking things. Fluid level normal. Idle pressure normal. Reverse and drive pressures as expected. Lifted the rear end off the ground. Reverse spins the wheels but as noted, with not enough torque to move the Ex. Drive spins the wheels and seems to shift through the gears but once it hits 30MPH or so, it coasts to a stop.
What questions should I be asking myself? I expect that I will be pulling the pan off. What should I look for if there isn't something big and hard in it? Any help will be appreciated.
Joe
The old valve body showed signs of gasket failure. There were cracks and it was generally brittle. There was nothing remarkable in the pan except the usual fines stuck to the magnet. Let it drip for days and cleaned off some stuck pieces of gasket material with acetone. While it was dripping I installed a drain plug in the pan. I used a replacement pan plug that has 1/2X20 threads and got a matching nut. Cut channels in three of the faces for drainage and welded it to the inside of the pan near the low area where the filter tub is. That will pay dividends. Also got a replacement low/reverse servo with the D-ring set. Also adjusted the bands along the way.
The new valve body came with a bonded gasket and some minor upgrades. It went in with no difficulty. I used an old valve body that I was given as a template to hold the screws as I did the removal. Given that I'm not that good at reading and tightening, I numbered the valve body screws with a paint pen in the torque sequence. Saved me a bunch of fussing when torquing the valve body screws. Did the tightening in three stages, ending at 97 inch pounds. I read enough threads that all reminded me to be sure to link the manual valve to the shift mechanism. Buttoned up the pan and filled it up initially with 6 quarts of Merc V. While the old low/reverse servo all but fell out when I loosened the bolts on the cover, the new one with the D-ring fit quite snug.
Started it up and the idle pressure came up to about 100PSI. Ran it through the gears, noticing that the pressure did the expected increase to 200 PSI in reverse. Also noticed the "clunk" of engagement and a drop in idle RPM. So far so good. Topped up the fluid with another quart, repeated the shifting and checked and added a little more. Here's where it goes to crap.
I put it in reverse to roll back off the ramps. No go. Seemed to pull OK in drive. Pushed it off the ramps and cleared the way, put it in drive and rolled off. About 50 feet down the driveway it seemed to go into neutral. Dragged it back with my F150 and started checking things. Fluid level normal. Idle pressure normal. Reverse and drive pressures as expected. Lifted the rear end off the ground. Reverse spins the wheels but as noted, with not enough torque to move the Ex. Drive spins the wheels and seems to shift through the gears but once it hits 30MPH or so, it coasts to a stop.
What questions should I be asking myself? I expect that I will be pulling the pan off. What should I look for if there isn't something big and hard in it? Any help will be appreciated.
Joe
