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The first Fleetwood Flair thread started in 2011. Documented install of Cummins 6bt and Dodge 46RH trans in a 1990 Fleetwood Flair RV. Really good service til winter before last when trans failed. The steel lines to atf cooler sprang a leak and lost atf and trans.

So this thread documents trans replacement. Bought a Allison 545 for three hundred came with adapter and flywheel. Not the most popular swap but we shall see. Is the last fully mechanical Allison trans and most durable some say. 4 speed even ratio spacing no overdrive gear.
Started today. Drive shaft out trans on trans jack bolts loose. 46RH out tomorrow. Will post more as progress...
 

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With no OD gear, that is really going to limit your highway speed. The AT545 was generally in vehicles that didn't travel over 55 MPH. Commonly used in school buses. If the 46RH gave good service it would seem it would have been a logical replacement. You could have gone a 47RH which had the lockup torque converter in addition to OD. Would probably be more fuel efficient. Can't blame the transmission on the broken cooler line. In the Allison line up a 1000 or 2000 might be better but definitely not as cheap.
 

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The Allison 545 arriving home early this summer. About 50 miles away from home in SE MN. Cost $300. This one has a parking brake on drive shaft. Came with dash shift lever. Came with 4 evenly spaced ratios no creeper gear and no overdrive.
 

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Discussion Starter · #4 · (Edited)
With no OD gear, that is really going to limit your highway speed. The AT545 was generally in vehicles that didn't travel over 55 MPH. Commonly used in school buses. If the 46RH gave good service it would seem it would have been a logical replacement. You could have gone a 47RH which had the lockup torque converter in addition to OD. Would probably be more fuel efficient. Can't blame the transmission on the broken cooler line. In the Allison line up a 1000 or 2000 might be better but definitely not as cheap.
Yes all you say is true. But cheep as I am a very dependable transmission cheep looks good to me. Gearing solutions include. 1. I generally do not drive RV over 55mph and max 60 is fine with me. 2. If I find a Dana 71 axle reasonable speed up maybe to much. 3. A drive line overdrive 1-1 and 1-1.3 ratios would work. The Flair has been winter home Yuma area for 10+ years. The drive there (from MN) and back is hot spring to hot spring and no hurry. The 46RH still operates just strange noise. I may rebuild sometime...
 

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Yes all you say is true. But cheep as I am a very dependable transmission cheep looks good to me. Gearing solutions include. 1. I generally do not drive RV over 55mph and max 60 is fine with me. 2. If I find a Dana 71 axle reasonable speed up maybe to much. 3. A drive line overdrive 1-1 and 1-1.3 ratios would work. The Flair has been winter home Yuma area for 10+ years. The drive there (from MN) and back is hot spring to hot spring and no hurry. The 46RH still operates just strange noise. I may rebuild sometime...
Some more progress pictures...the Allison AT545 left the Dodge 46RH right
Brown Art Gas Tints and shades Font


Three Cummins adapters;
Excuse me picture upside down. Allison to Cummins Right hand starter, The removed Dodge 46RH, the Allison to Cummins LEFT hand starter;
Automotive tire Road surface Grass Asphalt Font
 

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There is another possible bellhousing you didn't show. There are 2 of the SAE types with the starter on the passenger's side. One with the starter up high and the other about mid way. There is only the one style for the driver's side. Below is a photo of the 3rd type. Of course the starter is different on the left and right hand models.
 

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Discussion Starter · #7 ·
There is another possible bellhousing you didn't show. There are 2 of the SAE types with the starter on the passenger's side. One with the starter up high and the other about mid way. There is only the one style for the driver's side. Below is a photo of the 3rd type. Of course the starter is different on the left and right hand models.
Yes the two similar Allison adapters I have use three bolt starters same bolt pattern. The dodge adapter has a different three bolt pattern. The Dodge starter can be rotated to connect to the Allison adapters by using only two bolts. Looking at several Cummins starters about one third are two bolt mounting and others are three bolt. Anyone have experience using a three bolt starter using only two bolts ?

Second question same post. The Dodge has a heat exchanger that has an ATF in and out and a engine antifreeze in and out. Original swap was 6BT and 46RH as unit so I did not think much about that part. For this swap it is in the way of larger adapter and must be moved. Thinking about just removing heat exchanger. There is a trans radiator that will be in use for AT545. Any thoughts ? I will search for Allison AT545 cooling.
 

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The one on the right of the pic looks the same as mine. Was fitted with an AT545.
Housing casting number 3921300.
 

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How heavy is that Fleetwood Flair ? As an ex- Allison sales rep..............back when times were good, I'd do more homework before I continued with your change. And what engine was the Allison mated to ? Initially it didn't have diesel torque converters, so it was a slug, then when you backed off the throttle , it would freewheel .
 
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