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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: dchilds on October 17, 2012, 07:36:04 AM

Title: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: dchilds on October 17, 2012, 07:36:04 AM
We are in Laughlin NV - From NC.  Our MCI 7 Detroit Diesel 8V71 has a cracked transmission.  We need to get advice on who in this area works on these engins.  Thanks for any help that anyone can offer.
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: ol713 on October 17, 2012, 09:08:27 AM

  Hi;
     Sorry to hear of oyour troubles.   I also have a MC-7.
     If you can get to Las Vegas,  call Bob at B&B bus
     conversions.  If he can not help you then he will know
     who can help.
     I don" have a phone number for you.   Will try and look
     it up and repost it.
                                Good luck,   Merle.
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: Van on October 17, 2012, 09:20:55 AM
Maybe Clifford will jump in, as that's his neck of the woods (desert) until then maybe these folks can help  http://www.greatwesttruckcenter.com/?PageData=25930 (http://www.greatwesttruckcenter.com/?PageData=25930)
Where exactly are you, are ya'll dead in the water? There is also B&B Coach up here in Vegas, give Gary a call 702-873-4415. Please keep us posted ;)

    Van
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: ol713 on October 17, 2012, 09:31:14 AM
 Hi;
    I looked up some info for you.
    I assume you have a 4sp spicer in your coach.
    The info for B&B coach works is;
                          Gary  & Sandy Bennitt
                          4350 s. Arville St.
                          Las Vegas, Nv.
                          702/873-4415

    Another contact is;
                       HB Industries
                       9762 Silva Rd
                       El Cajon, Ca
                       Bob Rowsell  
                       619/561-9048
                       888/725-4461  

     Another contact is;
                       Don Fairchild   -- - -  Bakersfield
                       He had a spicer 4460 for sale.  He also
                       might know some one to install it for you.
                       Some one else on this board might have
                       a phone number for him.
                       Let us know how all this turns out.  
                                  Good luck,   Merle.  

Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: luvrbus on October 17, 2012, 09:53:33 AM
A&A Diesel in Mohave Valley about 20 miles from you 65 bucks a hr fwiw 928-768-4311 ask for Andy tell him I said call

good luck
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: bevans6 on October 18, 2012, 01:38:21 PM
Man, I am sorry I didn't have my computer for the last two weeks.  I literally just threw out a perfect Spicer 4 speed case, completely stripped, two days ago.  I got $25 for it from the salvage place.  I spent a morning stripping out all the gears so I could get the "dirty aluminium" price.  I would have happily given it to you for fun and giggles...

Brian
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: John316 on October 18, 2012, 01:51:23 PM
Quote from: luvrbus on October 17, 2012, 09:53:33 AM
A&A Diesel in Mohave Valley about 20 miles from you 65 bucks a hr fwiw 928-768-4311 ask for Andy tell him I said call

good luck

DC, first off sorry to hear about your troubles.

Second off, a little education. "Luvrbus" is Clifford aka bus "Yoda". If he says something, you can go to the bank on it. In this case if he suggest A&A, you can't go wrong with them. So you would tell them that Clifford told you to call.

Hope you get it fixed quickly.

John
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: Lin on October 18, 2012, 03:24:27 PM
I think I have a Spicer at Don's in Bakersfield, but it would need the clutch rebuilt.
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: TomC on October 19, 2012, 08:07:08 AM
Sounds like the right time to install an Allison HT740 automatic.  Good Luck, TomC
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: dchilds on October 22, 2012, 03:31:05 PM
Thanks for all of your responses. We have the trans out and are currently looking for a housing.  Appreciate all of the leads.  DC
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: RJ on October 22, 2012, 10:47:43 PM
DC -

If you might be contemplating an automatic, I have a friend who's got a used, but dyno'd, HT-754 five-speed Allison available.  It's out of an MC-9 that was owned by a well-maintained fleet in CA.

Send me a PM and I'll get you his contact info.

FWIW & HTH. . .

;)
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: beatsworkin on October 23, 2012, 09:11:24 AM
 RJ if DC is not interested in that Allison 754 I could be.  Also what is the 5th gear ratio?

Red
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: Stormcloud on October 23, 2012, 10:15:50 AM
FWIW I just installed an MT654 in my MC7 that previously had a Spicer 4 speed standard.

I had to install a different accessory drive housing on the rear of the 8V-71 to accept the larger ring-gear, which then required a custom-machined adapter for the smaller rear main seal to fit.

We also had to modify the rear mounts that bolt to the accessory drive housing.

My 4 belt-driven DN alternator wouldn't bolt up on the new drive housing, so it was replaced by a 100 amp 24 volt unit, belt driven off the front of the engine. Pretty much everything else just bolted up.

I replaced the 2 rear doors of the engine bay with 1 large door skinned with expanded metal, and installed a Hayden 2305 transmission cooler there. It cools the transmission well so far, but the acid test will be this winter on our return trip from Brrrrrandon, Manitoba to Yuma. I didnt want to dump the heat from the automatic into the MC-7 rads which are apparently borderline with a standard transmission.

I still have the Spicer 8844 transmission sitting here.....with a used clutch, and assorted parts. It's a long way from you.
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: TomC on October 23, 2012, 11:51:28 AM
Red-whether it be a HT740, or HT754, the high gear is 1:1.  Only the 4000 series has a .74 and .64 overdrive.  I looked into installing the HD4060 in my truck, but it would have been $10,000 more, and then you'd have an electronic transmission.  The HT740 is probably the most dirt reliable automatic ever made.  The HT754 is also reliable-but a bit more delicate because of the extra gear.  Good Luck, TomC
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: Dreamscape on October 23, 2012, 07:56:56 PM
And I thew a good one away a few months back, couldn't give it away then.

We went with an Allison 740, the best decision we could have made. It also meant a shorter driveline, which we had to have made complete new from scratch. Have put on about 500 miles since we made the swap and it runs great!

Now my DW doesn't have to listen to me talk like a sailor when I shift it! ;D
Title: Re: Transmission repair or replacement 8V71 4 speed Detroit Diesel MCI 7
Post by: luvrbus on October 23, 2012, 08:28:52 PM
While I love the 740 I think the 754CR is the way to go for a 2 stroke

1st gear  3:69
2nd gear  2:00
3rd  gear 1:58
4th gear  1:25
5th gear  1;00 

The second gear start 754 have a 2:96 second gear nice transmissions  JMO

good luck