| Author | Message | ||
| David Anderson (168.215.176.98) Rating: |
I have decided I want to change my Voith automatic transmission over to an Allison Automatic. I have a 1985 Eagle 10 6v92 silver with turbo. One shop wants to sell me an HTB748 with Electronic shift selection for about $7k plus installation. Another place I called quoted an HT740R for around $7250 plus install. Both quotes include transmission retarder. My Voith has a retarder on it. I asked about deleting the retarder and going with Jakes instead, but both quotes would be higher, and both shops said a retarder would serve me better for mountain driving with less maintenance than Jakes. I have to replace the shifting units no matter what I do. The Voith shifter and ECU won't interchange with the Allison. Also, I have to buy the rebuilt Allison outright as there is no core allowance for the Voith. What is my best plan of action, and is this about the right price? Both were so close, it must be about the going rate. My engine is fine, so no problems there. Anyone who has done this before I sure would appreciate the sharing of your experience. | ||
| Gary Carter (216.17.49.245) Rating: N/A |
Why the change? What is the cost of rebuilding the voith. Once done should be good for life. | ||
| David Anderson (168.215.176.149) Rating: N/A |
Gary, What is wrong with the Voith? Answer, nothing right now. I spoke with a shop in Houston that was referred to me from a post on the E-groups, eagle busnut site. My conversation with the gentleman didn't start out with questions about a change out. I was looking for the wiring diagram for the secondary panel next to the driver's seat in my eagle that is not in the shop manual I bought. I've been searching on and off for this diagram for a year now, without success. I'm trying to determine how the retarder circuit is configured. Anyway, this shop worked on the Houston Metro eagles over the years and he claims the voith transmissions were absolute mechanical disasters for Metro in the last couple of years the buses were in service. It got so bad that some buses were changed over to allisons and as it came closer to retiring the fleet, if a voith equipped bus failed they just parked it and auctioned it off. They finally auctioned off about 79 eagles in November of 1999 and that was the end of it all. He told me it would be folly to try to drive around the country in this bus with the Voith in it. Now keep in mind I didn't solicit this info and was not looking for a new tranny. I was looking for a wiring diagram. Curious about his comments, I pulled out Bus Conversion Magazine and called one of MAK's advertisers. I told the shop I had a Voith tranny that was working fine and was just snooping for a possible Allison changeover. He couldn't believe I'd be driving around with this in a bus without a wrecker following behind. His experience with the tranny has been as bad as described by the Houston shop. Parts are very difficult to find. As of what I know Cummins is the authorized dealer, but doesn't have a lot of experience in servicing the Voith because there are so few out there. So, here I sit wondering what I should do. I still have about a year to go on the conversion, so I have time to research a good solution. David Anderson | ||
| Dave Wheat (24.158.28.11)
Rating: N/A |
Dave: Of the commercial buses I drive, 3 have jakes and one has transmission retarder. The retarder has to be used carefully as it heats up the transmission fluid which is Not good. Never a concern when using the jake brakes. As a result, I rarely use the retarder although I would like to. Dave W. | ||
| Tom Caffrey (Pvcces) (12.146.33.9)
Rating: N/A |
Dave, it's funny how many people don't think about the waste heat generated when you're trying to slow something heavy down, isn't it? I haven't seen any reports about how hot a retarder gets the transmission oil, but I do remember running across information that oil has only about half the specific heat of water. Do you have a temperature guage for your transmission oil? If I was trying to get any use out of a retarder, that's what I think I would try. Everything depends on how quickly the oil can shed its heat into the cooler, I would think. Tom Caffrey PD4106-2576 | ||
| Dave Wheat (24.158.28.11)
Rating: N/A |
Tom: There is a temp gauge for the retarder and it comes up very quickly when retarding. I can't see it being used too much on a long steep downgrade because of the rapid transmission fluid heat build up. We have steep hills here in Duluth, MN. :-) Dave | ||
| DrivingMissLazy (65.207.109.140)
Rating: N/A |
A general question. There has been talk about Jakes and a transmission retarder. Is there anything like sticking a potato up the exhaust pipe to limit the amount of air coming out the exhaust. Would something like that work? Richard | ||
| Jim Ashworth (Jimnh) (172.139.57.251)
Rating: N/A |
Pac-brake already patented that one. They close off the exhaust to slow the vehicle. As to the temp rise, I drove commercially, several 45' MCI 102DL3's with transmission retarders. One slowdown to a toll booth and the temp was at the max recommended by the shop foreman. Using it on a long downgrade would be worthless. I'll stick with my Jake, thank you! Jim | ||
| Phil (204.89.170.3)
Rating: N/A |
I have an exhaust brake on my 22000 pound Monaco/260 Cummins/5 speed Allison. Works great with almost no need to use the service brake except the last 10-15 MPH. Don't know how they work on a two stroke or on the heavier vehicles. | ||
| Buswarrior (Buswarrior) (152.163.207.181)
Rating: N/A |
I'll wade in here with a little more info, just to balance the discussion. The retarder that I like is the one in the Allison B500R. The driver can control the degree of retarding, and choose whether it happens on accelerator pedal release or through the use of a multi-staged joy stick. With the B500R retarder set on full, and for full effect,in conjunction with proper gear selection, it will outbrake a sister bus with engine-brake. Driven both. Depending on age, you get at least four stages of retarding force. Now, there is no free lunch. The retarder, being a hydraulic device in the transmission, puts all that energy of motion into heat in the transmission fluid. The transmission has a cooler that is integrated with the engine cooling system. So, as long as you aren't trying to go and stop at the same time, the cooling system will take your heat away. Going down the mountain, the cooling system only has the transmission to contend with, since the engine is just loafing. You may have heard stories of MCI's frying their transmission fluid, which are true. There was a design issue with the cooling package. Not quite enough cooling capacity for the most severe operation. (Engineers, feel free to wade in here and condemn the state of current engineering school practices and the rotting influence of accountants on good product execution!) Easy enough for a busnut to fix on their own coach! And, maybe most importantly, as more and more municipalities pass noise legislation, a retarder is silent, and an engine brake will get you a big ticket. I dare say that Upper Rubber Boot, GA doesn't give a fig which RV club you belong to, they'll nail you like you are a trucker if your exhaust farts coming into town! remember, we're all in this together! happy coaching! buswarrior |
