A current US Syncro forum topic with acknowledgements to contributors, food for thought ....
Topic Post: Don't roll or bump start your syncro in reverse
I have a 1990 Syncro with an Adventure Wagon camper. About 3 years ago I was in a very remote area with a dead battery. At that time I was very lucky to start the engine by rolling in reverse. I have a few questions.
Was I lucky to beat the odds and have no apparent damage? The battery was dead because I left the lights on and the Syncro does not have an alarm to warn me of my error. Over the past 20 years I have done this at least 3 times.
How difficult is it to install an alarm when the lights are on?
Besides the main battery for the van my conversion has 2 deep cycle 6 volt Trojan batteries just for use in the camper and separated by a solenoid from the main system. On one occasion I tried to start the van by using jumper cables from these deep cycle batteries to start the van but it did not work. Why would this not work? Jim Wilson
Reply 2 The first time I did that (compression start in reverse) it cost me a tranny rebuild, about $2K.
IMHO If you have to bump start, use first gear, this is the strongest being right next to the pinion bearing or second for the higher ratio cranking, I would not recommend using 3rd as the teeth on this gear are quite fine. Granny and Reverse can't be used safely because they are hung out the front of the transmission a long way from the crown and pinion mesh and the intermediate housing is just not strong enough, the reverse idler gear in particular being supported by a shaft held by only a few mm of aluminium case, this is what usually breaks out. Aidan Talbot
Don’t EVER compression start a Syncro in Reverse OR Granny..The forces created can blow the rev idler gears out the bottom of the case…Not a pretty sight and very expensive…Use 2nd or 3rd. Daryl Christensen
So which IS the safest gear (tranny wise) for bump starting ... 1st, 2nd, 3rd or 4th?
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