Anyone know how to "flip" gears in a Eaton RTO?

[TheDrashStash]

My reasons are simple, I already have a RTO9513 and a M1084 with an Allison transmission. I was just quoted $1,600 for the output speed sensor and $611 for the transfer case wire harness and I'm sick of these transmissions. The Allisons are too expensive and have left me stranded multiple times.

I can use my RTO9513 for a core for a RTOO9513 or I can take a stab at flipping the gears to get that sweet .62 OD.

From what I can gather you switch the last 2 gears meaning you put 4th where 5th goes and 5th where 4th goes. Also the counter shafts are timed to the main shaft

The T-case will be a Oshkosh 55000 and I already have the 3.07 diffs

Does anyone know anything about this mod?

 

[simp5782]

My reasons are simple, I already have a RTO9513 and a M1084 with an Allison transmission. I was just quoted $1,600 for the output speed sensor and $611 for the transfer case wire harness and I'm sick of these transmissions. The Allisons are too expensive and have left me stranded multiple times.

I can use my RTO9513 for a core for a RTOO9513 or I can take a stab at flipping the gears to get that sweet .62 OD.

They are all very noisy in 13th.

From what I can gather you switch the last 2 gears meaning you put 4th where 5th goes and 5th where 4th goes. Also the counter shafts are timed to the main shaft

The T-case will be a Oshkosh 55000 and I already have the 3.07 diffs

Does anyone know anything about this mod?

Just buy the RTOO already done with a warranty

Gearman93 on tiktok has a video on the gear flip

They are also very very noisy in 13th.

I've got a feeling you are going to throw a driveline with the .62 and the .98 transfer. The Oshkosh 55000 doesn't like speeds over 68. I've had a hard time keeping a jackshaft in my 920 with the same setup but it's got double the power of your 1084.

Make sure you use HD50 SAE not 50w motor oil in the 55000. It's found in mystik brand from oreillys

 

[TheDrashStash]

Just buy the RTOO already done with a warranty

Gearman93 on tiktok has a video on the gear flip

They are also very very noisy in 13th.

I've got a feeling you are going to throw a driveline with the .62 and the .98 transfer. The Oshkosh 55000 doesn't like speeds over 68. I've had a hard time keeping a jackshaft in my 920 with the same setup but it's got double the power of your 1084.

Make sure you use HD50 SAE not 50w motor oil in the 55000. It's found in mystik brand from oreillys

Thanks for the fast response, I'll have to check out that tiktok. I might have a lead on a RTOO for $3,500 with a 1 year warranty close by if they ever call me back. They are hard to come by.
I don't like taking my truck over 65mph anyway lol

 

[Skyhawk13205]

That is frustrating, I had to replace my output speed sensor. The sensor just by itself was $1k, I had to drain the oil just to replace the sensor. For some reason the wires to the sensor start to get stretched then the connector dislodges. Mine had a contact that migrated from the weather pack connector. Also I don’t think having electrical components continually emersed in hot oil is good for reliability.

FADEC systems are great and work well till they decide to give up and quit at random.

 

[simp5782]

Thanks for the fast response, I'll have to check out that tiktok. I might have a lead on a RTOO for $3,500 with a 1 year warranty close by if they ever call me back. They are hard to come by.
I don't like taking my truck over 65mph anyway lol

LkQ will build the transmission in house with the warranty.

There are not many true RTOOs out there anymore they just gear flip an RTO on what they sell you. How do you know? A true RTOO your high gear is against the dash. An RTO that has been flipped its not on the dash.

I assume you are going to use the hydraulic clutch setup like the Freightliner Cascadia uses? Or are you going to use the air over hydraulic type the volvo VNL uses? Any hydraulic clutch will be a self adjuster and are alot more than a normal clutch. You will also need the inspection plate fork unit.

 

[TheDrashStash]

Anything that would get me out of this Allison. My truck "lurches" twice when going into 3rd gear so I fear it may need a rebuild sometime.

I have a wilwood clutch pedal that mounts on the floor and I think I'll need this kind of fork unit

https://www.vanderhaags.com/detailv...tSVwM59J8q4WAp6_mq1qIZxZUCNCyAERoC_-AQAvD_BwE

For now I can rob a speed sensor out of a parts truck to get my rig going. In the meantime I'm going to start collecting parts to get this manual system all put together

 

[simp5782]

Anything that would get me out of this Allison. My truck "lurches" twice when going into 3rd gear so I fear it may need a rebuild sometime.

I have a wilwood clutch pedal that mounts on the floor and I think I'll need this kind of fork unit

https://www.vanderhaags.com/detailv...tSVwM59J8q4WAp6_mq1qIZxZUCNCyAERoC_-AQAvD_BwE

For now I can rob a speed sensor out of a parts truck to get my rig going. In the meantime I'm going to start collecting parts to get this manual system all put together

You will want a HEMTT speedometer to work with the speedometer drive in the 55000 transfer case. They are on ebay.

You will need the m916a1 transfer case lever on ebay. They have it listed as an emergency brake cable unit. Or use the air shifter but they bind up bad.

You will need to have your drivelines redone to get away from your current 1610 units. Depending on what 55000 variant case you got. I'm sure you got the HEMTT version and not a PLS, HET, or M917 version

I have some short 1710 shafts you could use from your transmission to transfer case.

 

[DeMilitarized]

My reasons are simple, I already have a RTO9513 and a M1084 with an Allison transmission. I was just quoted $1,600 for the output speed sensor and $611 for the transfer case wire harness and I'm sick of these transmissions. The Allisons are too expensive and have left me stranded multiple times.

I can use my RTO9513 for a core for a RTOO9513 or I can take a stab at flipping the gears to get that sweet .62 OD.

From what I can gather you switch the last 2 gears meaning you put 4th where 5th goes and 5th where 4th goes. Also the counter shafts are timed to the main shaft

The T-case will be a Oshkosh 55000 and I already have the 3.07 diffs

Does anyone know anything about this mod?

Not to derail the whole thread but what were the symptoms of the failed output speed sensor?

 

[TheDrashStash]

You will want a HEMTT speedometer to work with the speedometer drive in the 55000 transfer case. They are on ebay.

You will need the m916a1 transfer case lever on ebay. They have it listed as an emergency brake cable unit. Or use the air shifter but they bind up bad.

You will need to have your drivelines redone to get away from your current 1610 units. Depending on what 55000 variant case you got. I'm sure you got the HEMTT version and not a PLS, HET, or M917 version

I have some short 1710 shafts you could use from your transmission to transfer case.

Thanks for all the advise, especially about LKQ. My local LKQ said that they will build out my RTO for me. As for the 55000, are they all the same? I found one that looks like it came from a non-military application, but the price is good

 

[simp5782]

Thanks for all the advise, especially about LKQ. My local LKQ said that they will build out my RTO for me. As for the 55000, are they all the same? I found one that looks like it came from a non-military application, but the price is good

No. They aren't. Some are narrow shaft cases. Some are 2in shaft cases that use 1710 yokes all around. The 2.5in shaft cases use 1610 front axle joints and 1810 on the jackshaft and rear output. The 2.5in cases also have a middle pump drive. Then there are 2.5in cases with a front drive pump and torque equalizer but they are what is found in the PLS

 

[TheDrashStash]

Not to derail the whole thread but what were the symptoms of the failed output speed sensor?

I had trouble codes 2251 and 2216 with the speedometer going out and it locking into its current gear. I swapped out the TCM with a good unit along with a transmission wire harness from the same parts truck. I just pulled the speed sensor and transfer case wire harness from the parts truck so hopefully I can get my 1084 running for now

 

[TheDrashStash]

No. They aren't. Some are narrow shaft cases. Some are 2in shaft cases that use 1710 yokes all around. The 2.5in shaft cases use 1610 front axle joints and 1810 on the jackshaft and rear output. The 2.5in cases also have a middle pump drive. Then there are 2.5in cases with a front drive pump and torque equalizer but they are what is found in the PLS

What about this?

Looks like one of the outputs is on the middle shaft and turns counter to the shaft below

 

[simp5782]

What about this?

Looks like one of the outputs is on the middle shaft and turns counter to the shaft below
View attachment 891348View attachment 891349

Narrow shaft case.

 

[TheDrashStash]

Narrow shaft case.

Is the narrow shaft no good? The Yoke on the middle shaft is concerning. Can that be moved to the bottom shaft?

 

[simp5782]

Is the narrow shaft no good? The Yoke on the middle shaft is concerning. Can that be moved to the bottom shaft?

Narrow shafts are full time 4x4 units since there no shift collar on that center shaft. They instead have a shift collar on the back output drive.
You can move the yoke to the lower shaft placement. It sometimes requires a different type yoke depending on the shaft diameter.

I wouldn't use it. The units found in the HEMTTs are generally pretty cheap at auction.

 

[TheDrashStash]

Narrow shafts are full time 4x4 units since there no shift collar on that center shaft. They instead have a shift collar on the back output drive.
You can move the yoke to the lower shaft placement. It sometimes requires a different type yoke depending on the shaft diameter.

I wouldn't use it. The units found in the HEMTTs are generally pretty cheap at auction.

I'm thinking this went to a concrete mixer truck with a rear mounted engine because the input yoke is on the back. Too bad because it's $1250. I'll keep an eye out for a HEMTT 55000

 

[simp5782]

I'm thinking this went to a concrete mixer truck with a rear mounted engine because the input yoke is on the back. Too bad because it's $1250. I'll keep an eye out for a HEMTT 55000

The input side doesn't matter. It can be front or rear. The internals of the cases are nearly all identical except for a few things. That narrow shaft case doesn't have a front axle engagement housing for air to actuate the front drive. So its a full time unit