Boston gear teardown!

[muddog16]

One part of the project I've been putting off is the rebuild of the Boston gear for the cooling fan system, after tearing this down, I'm surprised it worked at all........all of the bearings are shot, the only thing that was still good were the oil seals, it took several hours to disassemble with some heat all of the bolts came out even the oil plugs.   What I have is a Boston R-146 gear box, I've searched the internet for information and drawings with no luck!   I will probably have to look at each individual bearing for their numbers and use the Prevost numbers for the seals.......all of the shims for clearances are reuseable I'll just keep them.    If anyone has any information on backlash adjustment I'd appreaciate the information and any other bits of information I might need...............!  I'll add some photo's tomorrow morning, this was a rainy day project........!

[bobofthenorth]

Pat I apologize for sending anyone into Prevost's online parts book but if you have the patience of Job it will answer your questions.  I believe the gearbox assembly part number you are looking for is 550027.  You'll need a Prevost parts account to access the online parts book but if you don't have one just phone Quebec and ask them to set one up.  I've found that their pricing tends to be pretty good so don't count them out as a possible source for the parts.  Once you've got an account you can check the prices online.

[muddog16]

Bob, I've got a Prevost account, I just figured the bearings would be cheaper else where, but it doesn't cost anything to ask!...........I thought about calling Prevost, for the radiator dampner as a complete unit................I just don't have the courage yet!......lol...........they did knock my socks off on the radiator core, they were the lowest price I found!

[bobofthenorth]

My NAPA truck guy was able to cross Prevost brake part numbers to Meritor.  I don't think we've ever crossed any Prevost bearing numbers so I don't know if he could do that or not.  We bought bearings but that was a long time ago & we bought them from Prevost.  If you've already got a Prevost account then go to their Business Tools section and look for Prevost PARTner.  Its well hidden - I have to look for it each time but eventually it will load a Java applet that sort of works as a parts book.

[stevet903]

Prevost shows the bearings available from the NJ location in their online catalog.  The only thing that doesn't seem to be available is the gaskets for the covers.  

Here's a pdf that shows how to adjust a different brand (page 5), it's probably pretty similar for a Boston Gear.  Maybe a call to Boston Gear would get the proper specs....

http://www.vonruden.com/engr_library/gear_box_right_angle_pdfs/110_Gear_Box.pdf

Let me know if you need the Prevost part numbers for the bearings/seals...  I think all the bearings/seals will end up at about $120.  A new gearbox is about $800....

Steve

[muddog16]

Thanks Steve, I have a customer number but I've never used the parts ordering online.   I had to send them a request for a user name and password!

The gear box that I have is different from the ones on the PDF file you posted.  It's only 28 years old,  I hope they have parts, gaskets I can make........bearings I can find eventually........oil seals I definately need numbers that will match Prevost parts for those.   The old Boston gear box has a part number XM-146-1 on the bottom, my Prevost manual (the original that came with the bus) calls it a Boston R-146, with a complete break down of parts and numbers and how many of each item needed.......I'm sure Prevost will come through.

Again thanks for the help!

[bobofthenorth]

Once you get access to the online system it will take the part numbers from your old book.  Just take out any spaces or dashes and it should automatically cross to whatever the current number is.  At least it does for mine and mine is a year older than yours. 

[stevet903]

It might be easier to call them than to learn how to use the online system....  especially if you want to get this together this month.  Then you can get them to send you the parts CD as well (it's the only free thing you'll get from Prevost!!)  The number is 1-800-621-5519 and you'll need the VIN of the bus when you call.

[Dave B]

While I had the radiator out, I replaced the leaking seals on the Boston Gear R146 in my 91 Prevost.  I bought seals (#471649-9936) for the 1" shafts at the local bearing place.  The bearings and gears in mine were like new.  Usually you can find standard numbers on the bearings and seals and use these to get new ones.  I called Boston for setup instructions and was told that there were none.  I found a local authorized shop on Boston's web site and took the unit to them for setup.  They bought two shim kits from Boston and said that, per Boston's instructions, they used bluing on the gears to get the clearances correct.  They used Loctite 515 Anaerobic Gasket Eliminator (Same as Permatex Anaerobic Gasket Eliminator) when they reassembled it. 

The synthetic oil that is supposed to be used in these boxes is made by Mobil.  Prevost sells it for $50 per quart or you can get it at Grainger for $19 per quart.

When I was at Ft Worth Prevost one of the mechanics said that they don't repair the gear boxes but put in a conversion kit for the new style gear box for $1,200.  The new ones don't look nearly as stout as the old ones.

[muddog16]

Thanks Dave, that is the box I have in your picture, I'm sure that I will be able to find everything, it may take a few days,  I'm not in a rush, the engine won't be going in until around Sept(crossed fingers),  I've just been putting this off......the main thing holding me back was the removal of all of the bolts, and oil plugs which are already out with a little heat to help!  I'll look for a Boston shop to do the final set up, if I can't find the backlash and clearance adjustments!   It's not rocket science......I just need the information!  Is there a number on the gear oil from Mobile?

Since I posted this message, I've located the nearest Boston Gear Distributor, and I also found the Mobile oil number its SHC634.