Need Help Quick! M1008 Hard and delayed Shifting

[Commander5993]

Hey Everyone, I'm Short on time here.

I'm in AZ to pick up an M1008 with a TH400 Trans. It has been completely redone, and the trans and transfer case just totally rebuilt. I'm having a problem with hard shifts and they are delayed between shifts by 3-4 secs. |

I know these trucks may shift a little hard because of the shift points, but How Hard Exactly?

Also after driving about 4 miles, and seeing the hard shifts, I checked the trans fluid and found it to be low. I parked it and went got some fluid came back and brought it up to level, and over filled it slightly. Drove it around a bit in a parking lot, and rechecked. It seemed a little better, but still was shifting hard. We then drove approx 15 miles, and stopped at a hotel for the night. When we stopped, I noticed there was a small leak. I've got a 1700 mile trip back home, and I have got to know if there is something major wrong or what.

I'm taking it back to the guy I got it from last night. They are going to put it back up on a lift and check about the leak.

Any Help is much appreciated!!!!!!!!!!!!!
THANKS!!

 

[Commander5993]

I'll check this thread again before I leave here in a few minuets.
And if you reply, and I don't have time to log back in on this public hotel computer, Thanks in Advance!!!

 

[Warthog]

Sound like the vacuum line is leaking or not hooked up. Easy check.

 

[DrJekl]

Did you replace the original trans with a rebuilt unit or rebuild the original? I broke the tail end off mine and replaced it with a rebuilt unit from a gas engine. The governor from a gas a diesel engine are different according to my transmission guy. had the delayed and hard shifts with high RPMs, looked at the vacuum first, no leaks, adjustment did not help. Swapped the governor and the problem was solved. Paul said the weights could have been different causing the shift change. I don't know much about transmissions but this swap seemed to work.

 

[Commander5993]

Hi Guys, Thanks for the replies! The trans was the original trans, just fully rebuilt. The fluid level was overfull, my fault got in to much of a hurry yesterday, especially when i didn't seen any fluid on the stick the first couple of checks when filling. Anyway, the guy I got it from told me to take to a shop just down the street from him. So I did that yesterday morning. They checked it, pulled some fluid out, cleaned off the whole bottom of the trans. When they had the truck up on the lift, they showed me where it was coming out of the metal overfill line, and then blowing around underneith. I thought, and was hoping, that that was the problem with the leak, and I thank the heavenly Father Yahuah that it didn't blow a seal or anything.
After I left, I drove it around 15-20 miles at a time, and then would recheck and see if it was leaking anymore. looked good. Done that about 3 times on my out of phoenix. I made it to albuquerqueNM last night about 11:45pm.
Still have the hard shift with the trans, but not quite as bad as it was when it was the day before yesterday when I first picked up the truck and the fluid level issures. I'm going to check the vaccume lines like you guys suggested before I leave out of town today. Got to go pick up the deuce here also before I leave, and check it out as well.

Also i wanted to ask: What is the original tire size on the M1008??? I think the tires may not be original size as the Speedometer is reading about 4 mph slow. When it shows 59mph my GPS shows 55mph. The GPS was also confirmed by my brother in the chase vehicle, as he was also showing 55mph at the time.

The guy I got the truck from, and someone here on SS, both said that 60mph was the top speed of the truck. So I kept it between 55 and 60 according to the trucks speedometer just in case.

I think I already know the answer to this question, but I want to make certain. Is it safe to keep the truck 55-60mph even when going up long steep interstate inclines/hills/mountains? I mean will it push the engine or any other componet to hard?
Sorry for all the questions, I'm just trying to use the hotel computer this morning, and have to leave here very shortly.
Thanks for All the Help Guys!!

 

[AceHigh]

My odometer is correct but the speedometer can read all over the place.

 

[Warthog]

Also check the vacuum valve on the IP.It may be out of adjustment.

The stock tires on a M1008 are LT235-85R16

 

[ken]

SLOW DOWN!!!! over revving a 6.2 for long periods will get you a busted crankshaft!! Trust me i've broke a few. Also check your harmonic balencer. Look at the rubber in between the hub and outer ring. When these go bad it will scatter the engine. I usally run in the 50 MPH range. With short bursts to 55. Running a low geared MV at 55MPH is about the same as driving a civi truck at 100 MPH. Just not a good thing to do.

 

[Commander5993]

SLOW DOWN!!!! over revving a 6.2 for long periods will get you a busted crankshaft!! Trust me i've broke a few. Also check your harmonic balencer. Look at the rubber in between the hub and outer ring. When these go bad it will scatter the engine. I usally run in the 50 MPH range. With short bursts to 55. Running a low geared MV at 55MPH is about the same as driving a civi truck at 100 MPH. Just not a good thing to do.

55mph is overreving??! I had two people tell me 60mph on highway.

Well the truck has the stock tire size, I don't know why it is registering 4mph faster on the speedometer than what it is actually traveling. When the speedo saids 59mph, it is actually traveling at 55mph. Anyway, guess I'll have to slow down to 50 then.

Thanks for the correction!

 

[chevyCUCV]

HAHAHA i was going to tell you to speed up!
I like 65 and there are way too many arguments over it. Drive however you **** well please and dont worry about the engine blowing unless you have a bad harmonic balancer.
And i think all the speedo's are off by a little.

Put your foot to the floor and enjoy the music!

 

[hndrsonj]

HAHAHA i was going to tell you to speed up!
I like 65 and there are way too many arguments over it. Drive however you **** well please and dont worry about the engine blowing unless you have a bad harmonic balancer.
And i think all the speedo's are off by a little.

Put your foot to the floor and enjoy the music!

So just out of curiosity, in your sig line you show a M1008 with a blown engine; did you buy it with a bad engine or did it happen at 65MPH?

 

[chevyCUCV]

Second time someone's said that,
I should put a note under it "I didnt do it"

I dont want to over m1008 speed in another thread. Just drive and dont think about it, or stare at your speedometer the whole time to make sure you dont blow your engine. Everyone can do as they please, i just think its MISINFORMATION to tell people that 6.2's cannot rev.

 

[hilber]

Second time someone's said that,
I should put a note under it "I didnt do it"

I dont want to over m1008 speed in another thread. Just drive and dont think about it, or stare at your speedometer the whole time to make sure you dont blow your engine. Everyone can do as they please, i just think its MISINFORMATION to tell people that 6.2's cannot rev.

I agree with you.

 

[Commander5993]

Ok... So How many people here do 55mph in their M1008 CUCV 's and have not had any problems with over revving the engine?

The CUCV seems that it will do 55mph easy, but I just dont want to blow the engine or other. Also if I can do 55mph in the M1008, then I can keep up with my brother in the M35A2 Deuce, which we picked up in NM, and stop slowing him down to 50.

We're currently in Oklahoma city, and we still have just over 700 miles to get to my home in crawfordsville, IN. So a little extra speed would be nice, even if it is only 5mph.

Sorry to but I just want to know for sure before I push a truck that we just picked up and are used to yet. Especially when we still have this far to go, as I don't want a 700+ mile towing bill Let alone having to rebuild the engine after I get home, especially since the engine only has 10600 original documented miles when we picked it up. I've put almost 1000 miles on it so far, since we I picked it up in AZ.

Thanks All!!

 

[ABN173]

I have had my M1008 for three years typically I have no issues at 65-70 mph in order to perhaps pass a slower truck/traffic. Most of the time I can travel 55-60 mph just fine even on extended trips. Now here is the the thing M1008's are geared lower they were simply not meant for high speeds. I don't believe you have to slow down to 50mph though.

Best of luck,
Dale

 

[Terracoma]

If the truck has stock tires (235/85R16) and stock rear axle gear ratio (4.56:1), then you will only be turning ~2800RPM in third gear at 55MPH.

Gear Ratio Calculator ... IMO, I think you're fine.

 

[Commander5993]

Thanks Guys for all the help! We made it home late yesterday evening. Just kept it at 55-60mph according to the speedometer, which was showing as 50-55mph on the gps.

I would have posted something here a few days ago, but the internet at the hotels was a complete joke. I still have the hard shifts from 1st to 2nd and from 2-3rd, but I still have to check all of the vacuum lines and other components. All in all, didn't have anymore real problems. Just have a lot of maintenance and things to check to be sure the truck is in full working condition.

Thanks Again Everyone!