FMTV High Speed Gears

[Awesomeness]

45 MPH (about where mine shifts to 7th) becomes 57 MPH.

Ill have 3.07's but will stick with 55-60 to keep engine and MPG happy.

On your truck, is 55-60 MPH just after the shift into 7th, at the minimum RPM?

 

[1951M1078]

Don't forget we have the "tire" issue also.

Newer tires = +mph.
Older tires = -mph.

 

[pontiac62]

Don't forget we have the "tire" issue also.

Newer tires = +mph.
Older tires = -mph.

Stupid question what’s considered new tires and old?


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Man of few words

M1081 LVAD

 

[1951M1078]

Over 10 years = display only.
Under 5 years = 60mph +- imo.
2018 = new= 65-70 mph imo

 

[deshet]

I guess I need to research the tire issue although I may have already experienced it. Blown tire for no reason traveling between Alabama and Virginia at 55-58 MPH. It was also an extremely hot day.

I was about 600 miles into the trip when the tire blew

 

[mkcoen]

I guess I need to research the tire issue although I may have already experienced it. Blown tire for no reason traveling between Alabama and Virginia at 55-58 MPH. It was also an extremely hot day

Do you have the Michelins or GoodYears?

 

[deshet]

I have Michelins X tires are the Goodyears better?

 

[mkcoen]

I have Michelins X tires are the Goodyears better?

I’ve been told the Michelin’s are only rated for 45mph. That was just hearsay but on page 62 of the Michelin Truck Guide they say max speed of 50mph. Now given that these tires are likely well past their date codes I'd say 45 would even be pushing it.

https://www.michelintruck.com/assets/pdf/2010_TruckTireDataBook_jul.pdf

 

[deshet]

https://www.michelinb2b.com/wps/b2bcontent/PDF/XML_DataPg.pdf

It looks they are rated fairly low 50 for the xml what is the Goodyear rating

 

[mkcoen]

https://www.michelinb2b.com/wps/b2bcontent/PDF/XML_DataPg.pdf

It looks they are rated fairly low 50 for the xml what is the Goodyear rating

Well you found better data than I did. The big difference in the tires is the tread. The Michelin tread is designed more for off road while Good Year is wider and flatter so better for pavement. Again, most of these tires are OLD so unless you're running new ones or ones past their date codes but stored indoors in climate controlled conditions, you're taking a big chance at governed speeds let alone what the High Speed Gears are capable of.

 

[coachgeo]

https://www.michelinb2b.com/wps/b2bcontent/PDF/XML_DataPg.pdf

It looks they are rated fairly low 50 for the xml what is the Goodyear rating

as has been stated by others.... don't go by some single rating.... go by the detailed rating put out by manufacture. Detail rating is based on air pressure and weight on axle. AKA-- speed rating varies based on those two variables.

 

[deshet]

Has anyone tired running [FONT=&quot]385/65R 22.5? I can get these all day for decent money barely used. They don't have an extremely [/FONT][FONT=Helvetica Neue, Helvetica, Arial, sans-serif]aggressive[/FONT][FONT=Helvetica Neue, Helvetica, Arial, sans-serif] tread but they will work for service roads. The Power Company has large class 6/7 4x4 trucks that have good Highway Speed; I will see what tires they run also. I basically want a service road capable RV that can get through the woods but I am not going to get into anything crazy.

[/FONT][FONT=Helvetica Neue, Helvetica, Arial, sans-serif]Will a bus rim fit on a LMTV? I guess I will research what tire they run on the custom built global expedition vehicles.
50 MPH isn't going to get the job done.
[/FONT][FONT=Helvetica Neue, Helvetica, Arial, sans-serif]
Thanks[/FONT]

 

[scottmandu]

Has anyone tired running 385/65R 22.5? Thanks

385/65R22.5 are 43 inches in diameter so you will loose 3 inches and won't do anything for higher top speed.

 

[simp5782]

Has anyone tired running [FONT=&quot]385/65R 22.5? I can get these all day for decent money barely used. They don't have an extremely [/FONT][FONT=Helvetica Neue, Helvetica, Arial, sans-serif]aggressive[/FONT][FONT=Helvetica Neue, Helvetica, Arial, sans-serif] tread but they will work for service roads. The Power Company has large class 6/7 4x4 trucks that have good Highway Speed; I will see what tires they run also. I basically want a service road capable RV that can get through the woods but I am not going to get into anything crazy.

[/FONT][FONT=Helvetica Neue, Helvetica, Arial, sans-serif]Will a bus rim fit on a LMTV? I guess I will research what tire they run on the custom built global expedition vehicles.
50 MPH isn't going to get the job done.
[/FONT][FONT=Helvetica Neue, Helvetica, Arial, sans-serif]
Thanks[/FONT]

Most super single 22.5s are hub pilot too. Might find some budds laying around. Super single wheels will cost you too. The offset super single wheels on my trailer are common accurides at 820$ each

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[MonkB]

Do you know if he wants or plans to sell? I would like to get a set. Oh and who is Joe?

This must be Joe at Das Mule (Mule Expedition Outfitters)...he's got two LMTVs and one (at least) already high-speed-geared. I'm sure that set is for one of his rigs.

 

[Ornduff]

I have a '98 1078. I have been looking into the high speed gears reading this entire thread etc. I was double checking tags on my axles and I think my truck has different axles. and I hope they are possible to add the high speed gears to. please educate me.
what I have.
Rockwell International
Cage code: 3WXD8
Part Number: 12414246
Date of Mfr: 7/26/2009

second tag;
Model: RF12611NFSF7
Customer No: 12414246
Ratio: 780

I was informed by the person I purchased the truck from that this was a training truck at Camp Shelby and the truck was refurbished in 2009. hence the new axles, front and rear. being that I don't see any Meritor badges, I have different setup than normal?
Any help is appreciated

 

[scottmandu]

I have a '98 1078. I have been looking into the high speed gears reading this entire thread etc. I was double checking tags on my axles and I think my truck has different axles. and I hope they are possible to add the high speed gears to. please educate me.
what I have.
Rockwell International
Cage code: 3WXD8
Part Number: 12414246
Date of Mfr: 7/26/2009

second tag;
Model: RF12611NFSF7
Customer No: 12414246
Ratio: 780

I was informed by the person I purchased the truck from that this was a training truck at Camp Shelby and the truck was refurbished in 2009. hence the new axles, front and rear. being that I don't see any Meritor badges, I have different setup than normal?
Any help is appreciated

Rockwell built the axles then Meritor bought out Rockwell's axle division. You have standard LMTV axles, nothing special. Rockwell, Meritor, and Axletech all made those axles. They are for all intents and purposes the same, the only difference is early axles had a fabricated steel housing and the later axles had a cast ductile iron housing.

 

[Ornduff]

Thank you, so all the same parts that everyone else is using still works. perfect.

 

[steve6x6x6]

This must be Joe at Das Mule (Mule Expedition Outfitters)...he's got two LMTVs and one (at least) already high-speed-geared. I'm sure that set is for one of his rigs.

No, this is Joe Goodenough with Journey Offroad in Washougal, WA.

 

[Ornduff]

Could someone please help me identify the axle position on my diffs please. Pardon my ignorance, I am still learning the differences between these rigs.
trying to get pic to load...