New Member, New truck and A Trans Question

[Carrera911]

Hello all, I've been lurking this site for about almost 4 months during my EUC wait and now have 2 HMMWVs. I towed one back on a Uhaul galvanized trailer and it WILL NOT fit without unbolting the fender. Anyway, towed it home behind my H2 from Montgomery to Atlanta. I've gotten most the basic items taken care of with the exception of the trans. It shifts fine through all the gears, only it goes 1-2 at ~5 mph and 2-3~ 25mph at WOT. These are only approximations but it seems to shift way too early. Also the kickdown doesn't work at at all and lugs the engine up hills at 30 in 3rd. All the gears shift fine manually. I think it has to do with the shift point adjustment but can't seem to find anything in the TMs or on here.
Anyway, thanks for any help, this site has been a great resource and will continue to be while I put a turbo 6.5/ 4spd takeout into my other non runner.

 

[Tracer]

Welcome aboard from Nevada.

 

[ageregunner]

Welcome from PA.

 

[Retiredwarhorses]

Hello all, I've been lurking this site for about almost 4 months during my EUC wait and now have 2 HMMWVs. I towed one back on a Uhaul galvanized trailer and it WILL NOT fit without unbolting the fender. Anyway, towed it home behind my H2 from Montgomery to Atlanta. I've gotten most the basic items taken care of with the exception of the trans. It shifts fine through all the gears, only it goes 1-2 at ~5 mph and 2-3~ 25mph at WOT. These are only approximations but it seems to shift way too early. Also the kickdown doesn't work at at all and lugs the engine up hills at 30 in 3rd. All the gears shift fine manually. I think it has to do with the shift point adjustment but can't seem to find anything in the TMs or on here.
Anyway, thanks for any help, this site has been a great resource and will continue to be while I put a turbo 6.5/ 4spd takeout into my other non runner.

View attachment 643564

these trucks are not speed demons...so even once you get it dialed in, don't expect miracles.
not sure if you have ever driven a HMMWV before you bid and bought...the shifting pattern is normal.

 

[Carrera911]

Thanks for the input, I got around to some diagnosing just using past experience and found that the throttle cable had too much slack. Adjusted it so now the pedal has no play and goes far enough to engage the kickdown switch. It holds gears long enough to stay in the power band and downshifts when needed. That plus the throttle actually opening 100% gives this truck pretty decent acceleration for what it is.

Last problem to sort out now is the oil pressure gauge. On cold starts it idles at 15psi and then 10psi warm. The problem is that it never goes over 20, maybe 25 even at high RPM. I went through the TM and verified the gauge responds correctly to grounding the signal and open circuit. I would just replace the sending unit only it's brand new and shiny so someone has been through this recently.(Probably November 2014 when this truck was overhauled). Autozone doesn't rent test gauges and Harbor Freight is an hour away so its gonna be a pain to find a test gauge.

Is it possible the pressure is that low at 28k with a fresh oil change?

 

[whatadeuce]

Welcome from FORT LOXAHATCHEE, located in the badlands of South Florida,

 

[MarkM]

You sure don't want her to kick down at highway speeds so be careful with that. These things shift early as they make full torque at 2K. Oil pressure seems low but maybe the gauge is bad. Mine is the other way 60 to 70 PSI at idle and pegged 120+ off idle so my gauge is off. I am installing a tach in mine so I know what she is running.

Good luck with the ride.

Mark