m1028 shifting fast with 37oz

[marks86]

I just put 37inch oz tires on my m1028 and now it shifts from 2nd to 3rd almost instantly as in I don't have a second gear anymore I cant seem to figure out why

 

[Westech]

Sounds like you need to get a new transmission modular or tps on the injection pump. Also check all the vacuum lines. Sounds like signal is lost to the modulator or something took a dump.

 

[markg]

here is one way to do it. pull plug with 2 vacume hoses running to the tps. be careful, its plastic. tps is the black thing attached to the injection pump on the passenger side. leave it off and go for a short drive. transmission should not shift until rpm gets close to redline. it will make a forced shift to second and then high. if you still have all your gears then you need to adjust your tps for less vacume. hook vacume connector back up, loosen the 2 screws and rotate the body of the shift actuator in the opposit direction. tighten and go drive, see what changes. it should shift later. adjust for your personal preference. if your truck shifts to soon you have plenty of vacume.

 

[marks86]

I have a new trans modulator, I will check the TPS, But I know I have all my gears because the trucks shifts manually without a problem

 

[cliffyp]

Get a pressure gauge and connect it to the drivers side port on the trans. If the trans is not making the correct pressure it will shift too soon or late.

Was your new vacuum modulator working prior to the tire change? Simply changing tires shouldn't cause the trans to shift early. If it was all working properly before and then changed with the tire change, it's just coincidental. Kind of like when my alternator stopped charging when I changed my oil.

Double check your vac system, seems like that is generally the culprit.

 

[Skinny]

Could be stuck governor too

 

[marks86]

This is annoying the living **** out of me I just put a different VRV off another truck I have that I know works set it right in the middle and still shifts the same Im in third gear by fifteen mph The truck shifts manually firmly but smooth as butter My kickdown switch is not hooked up not sure if that has anything to do with it

 

[marks86]

ps I had a m1008 with a vacuum leak somewhere and I felt what its like to have low vacuum when it shifts hard and late, its not like that at all its almost like Im starting out in second gear and I only have one shift, but in reality my 2nd gear is there for a then instantly shifts to third

 

[cliffyp]

Take the governor cover off and check the governor.
Check your pressure.

They are both fast checks. Rule them out and you have fewer variables as to what is causing the problem.

 

[marks86]

I have been super busy at work so I haven't had a chance to check the governor but what I did find is the kick down solenoid is not working Not sure if this has anything to do with it but Im going to replace this first and for most

 

[Westech]

I have replaced a few vacuum pumps on the old 62's also. Really if you have not fixed/replaced it on a cucv good chances it's ****ed

 

[MarcusOReallyus]

Take the governor cover off and check the governor.
Check your pressure.

They are both fast checks. Rule them out and you have fewer variables as to what is causing the problem.

?????

Well, that's sure a stupid way to solve a problem with a vehicle! You want to do TESTS? As in, actually THINK through the problem logically?





Anybody with any sense knows the way you solve a vehicle problem is to log on to a forum and ask other people what parts THEY have swapped out when they had a similar problem, then start swapping parts. If you're REALLY smart, you might take a few guesses and swap a few parts before asking. It's best if you start with the most expensive parts.

You obviously don't know much about fixing vehicles!

 

[marks86]

ok so I fixed my kickdown situation, also I checked the governor looks fine plastic gears still there, Still at a stand still here

 

[marks86]

can someone tell me how much pressure I should have at the rubber hose that connectors to the trans modulator on the side of the transmission or show me a pressure chart of something of how much pressure at what location..... I have a hair under 15 there, and I have the same reading at the out port of the VRV so I have to assume this problem is not vacuum related

 

[marks86]

FIXED IT!! the transmission modulator was way out of adjustment, thanks everyone for the imput