Another Mercomatic Question

[RalphG]

For those that run Merc/Fordomatics. Is it just mine or are they all pretty weak in reverse? I can recall even as a kid riding in the back seat, when my dad parked the 52 on a nose down parking location it was a real struggle to get the old Merc to back up. I was reminded of it again recently when I went to turn around at a crossroad. Had to reverse and the front wheels must have been up against a ridge or something and I could not move in reverse. The engine would not rev up no matter what position of the gas pedal. Just laboured and stood still. I had to rock it forward a few inches and then was able to back up. Fluid level is fine and no sign of slippage. Once it is wound up a little it speeds along just fine in reverse. It is just overcoming inertia that seems such a struggle. Is the old flathead just that weak or is this a characteristic of the mercomatic?

 

[51 MERC-CT]

Have you taken corrective measures in regards to the throttle rod adjustment yet?
Not sure, but if you correct the throttle rod the reverse situation may correct itself.

 

[RalphG]

Have you taken corrective measures in regards to the throttle rod adjustment yet?
Not sure, but if you correct the throttle rod the reverse situation may correct itself.

Yes, I have experimented a bit with lengthening/shortening the throttle rod to transmission. I could not really say there was a noticeable difference. I notice the clevis was turned quite far onto the rod before I even started adjusting. I went several turns in each direction.
I was reading a thread (old) over at H.A.M.B. and a picture there has me wondering if the rod is installed upside down on mine. Haven't checked yet but seems to me mine has the curve the opposite way to the one in this photo.
http://www.jalopyjournal.com/forum/threads/adjustment-of-merc-o-matic-more-power.943381/

 

[ookpik]

I suspect you have oversize tires touching on the frame? or other part on a tight turn.

 

[RalphG]

I suspect you have oversize tires touching on the frame? or other part on a tight turn.

Yes, I noticed the P235-70s did rub on the frame when I had the steering wheel cranked right over but I think this reverse weakness is still there even on a straight course. I'll be testing that theory out you can be sure.
And that kickdown rod, I checked mine and it is straight, not slightly curved like the one in the photo I borrowed.

 

[40 Deluxe]

Possibly binding up because in two gears at once? Jack up the rear end, start the engine, put it in reverse and see if the wheels rotate freely and if the engine revs up easily. Shift linkage could be out of adjustment. Also, I vaguely remember a bulletin from years ago the effect that there is an aluminum insert of some kind in the front of the output shaft that can get out of position and cause problems.

 

[RalphG]

Possibly binding up because in two gears at once? Jack up the rear end, start the engine, put it in reverse and see if the wheels rotate freely and if the engine revs up easily. Shift linkage could be out of adjustment. Also, I vaguely remember a bulletin from years ago the effect that there is an aluminum insert of some kind in the front of the output shaft that can get out of position and cause problems.

I've wondered about the possibility of it being in reverse and low at the same time too. Although low works fine, just reverse is sluggish. Maybe a band adjustment is needed? Low to drive manual upshift is really harsh yet drive 1-2 upshift is so smooth as to be unnoticeable.

 

[bbrocksr]

Possibly binding up because in two gears at once? Jack up the rear end, start the engine, put it in reverse and see if the wheels rotate freely and if the engine revs up easily. Shift linkage could be out of adjustment. Also, I vaguely remember a bulletin from years ago the effect that there is an aluminum insert of some kind in the front of the output shaft that can get out of position and cause problems.

That aluminum insert was called an oil delivery sleeve, when the piston type rings that run inside of it get worn the oil pressure can slip by and apply two gears at once causing a severe drag.

Bill

 

[RalphG]

That aluminum insert was called an oil delivery sleeve, when the piston type rings that run inside of it get worn the oil pressure can slip by and apply two gears at once causing a severe drag.

Bill

I guess after 60 years there could be some wear on those rings. I don't plan to open it up at this point but I may look into checking a motors manual for the band adjustment.
Jacked up the rear end and ran it today. Of course it runs easy in reverse when the wheels are off the ground. Wheels turn some when it is in neutral too.