Feasible to swap 8V71 w/ 60 Series

[Bill Gerrie]

We had a lot of issues with the New Flyer buses. The last thing was to replace all the ZF trans with V731 and a reverser between the engine and trans. The ZF would only last a month or so with all the stop and start of transit use. $25k for a rebuild so that made the V731 a viable option.

[TomC]

It just amazes me how the transit buses used the 6-71 or 6V-71 with just a 2 speed Allison transmission from 1946 (?) until 1977 when the V730 came out. Talk about rugged engines and transmissions-I imagine hundreds of thousands successfully used. Good Luck, TomC

[luvrbus]

They were high maintenance though when I would visit my buddy at Houston Metro they would have 20 to 30 rebuilt ready for change outs the 6v71's were good for about 80 to 100 k miles and the Vs and super VS were hit and miss.He was a happy camper to see the 8v71 and the v730, then he had to hire welders to keep the frame welded on the new buses I forgot who made the buses .Tom the 2 speeds were not made by Allision
those were made by GM fwiw

[RJ]

Tom, the 2 speeds were not made by Allision, those were made by GM.

Clifford -

Hmmmm. . . Then why does the VH/VS service manual that I have say "Allison Transmission Division, General Motors Corporation" on the inside front page?

[luvrbus]

I don't why yours say that or why mine says made by GMC Truck and Coach ,I know I could never buy the solenoids from Allison always had to get those from large GMC truck dealer.I was always told the VS was designed by GM but it could have been built by Allison I don't know for sure,it was around for years even with the problems,the guys at S/S called it the Power/Glide for buses,


I change one to V730 in a Fishbowl once the guy couldn't find the right fluid and used Dexron   

[CrabbyMilton]

GM owned ALLISON(sold them in 2007) back then so if you called it one or another it was pretty much academic. I think that GM stressed the ALLISON name when they sold the transmissions to competing bus builders same with DETROIT DIESEL vs. GM.

[TomC]

On my AMGeneral 10240B, the B was second generation based on the Flyer D800-which was a T drive. But all transit companies were using V drives, so AMGeneral built the transit bus with V drive. But the offset weight and all the weight at the rear end caused the engine cradle to crack. Hence on the B model like I had, you could see all sorts of reinforcing triangles and other shapes welded into the frame to keep the cradle in one piece. The original 8V-71 had 254hp and 680lb/ft torque. After turbocharging and air to air aftercooling, it put out 375hp and 1125lb/ft torque. It performed about like an MC-5. Good Luck, TomC

[luvrbus]

GM owned ALLISON(sold them in 2007) back then so if you called it one or another it was pretty much academic. I think that GM stressed the ALLISON name when they sold the transmissions to competing bus builders same with DETROIT DIESEL vs. GM.

Yep I have valve covers that have GMC.GM and Detroit embossed on the covers