Warning: Bad to bump start and skip gears
 

Posted these questions on HT and got the following response.
Just a heads up.



Is it bad to shift from 1st into 4th, assuming you are not revving 1st too high. My gears are really long...4spd std?

I recommend either shifting to neutral and letting out the clutch to rev match fourth gear or push in the clutch, shift 2-3-4, and let out the clutch. It is easier on the synchros.

Is it bad to coast in neutral?

It is OK to coast in neutral. Make sure the clutch is out to keep the input shaft spinning. This ensures lubrication. I usually coast for shorter periods by depressing the clutch with the transmission in gear. For longer periods, I shift to neutral.


Is it bad to coast with engine off, and bump start?

Don't bump start. You can really stress the axles. If you do bump start, use the highest gear. Coasting with the engine off also cuts your engine lubrication. So, you are restarting each time. It is not as bad as a cold start, but I don't recommend it.

Def rev match if you're
 

Def rev match if you're doing anything serious with rpm changes, that's my rule. And we always try to bump start in the highest gear anyway, I've never felt it to be a stressful event when I've done it. And the neutral advice makes sense, don't want to wear the throwout bearing with the clutch in.

Shifting from 1st to 4th or
 

Shifting from 1st to 4th or 5th is ok if you let the engine rev down a bit - there is enough drag on the clutch that the slower engine speed will also slow the clutch disk down and just pause in neutral before going into the next gear. With the Clutch pressed in the clutch disk spins at the speed of the car times the gear ratio that you are in. Going fast and putting it in first gear really spins the clutch disk and the throwout bearing. It can explode the clutch disk if you are going too fast. Throwout bearings usually don't wear out much anymore as better ones are being used now. Most of the gears are turning from the axle end and they are located low in the gear box and throw a lot of oil around to lubricate everything. The input shaft not turning is not a problem. The bump starting is turning the crank from the center and is even easier on the main bearings than the starter BUT it is a start without oil pressure so there is unlubricated wear going on for a fraction of a second and probably with HOT oil which is thinner than cold oil but there could also me more of it? Don't pop the clutch too fast either as it does load the axles and CV joints and use higher gears at higher speeds as you already know.

Quote:Don't bump start. You
 

hm... interesting my axles get banged when i bump start at really low speeds like 15 km/h or 10 km/h in 2nd or 3rd sometimes. 4th I rarely get a bang and 5th is usually smooth but sometimes rev goes a little to high. So far 4th has been very good to me....

but that means i'll have to bump start when my speed gets below 30km/h... then idle drats! Aw man a few mpg or a new axle Ill dedcide hMMMMMMMMMMMMM

as for lubrication that's what synthetic mobil 1 0-20w oil for hybrids are for! Works for regular cars that support 5-20 like mine but I yet have to make the switch!

plus I heard putting it in your tranny fluid gives it boost too! maybe more silky bump start?

With my project I'm using
 

With my project I'm using 5w20 (down from 5w30) for the time being, until I can find some 0w20, :(

Anyway, phill, you can get autozone remanufactured axles with a liftime warranty so you can break as many as you want, :)

Re: With my project I'm using
 

I have a stockpile of 0W-20. I might be able to spare some for you are interested.

Re: With my project I'm using
 

I tried changing to 1/2 5w-20, but it had no effect on MPG that I could tell

since this threada bout the
 

since this threada bout the fear of bump starting i'll add to other people's remarks

hmmmmmmmmm svoboy i didn't know axels were that cheap to begin with haha.

Saving a few mpg Yeah you
 

Saving a few mpg Yeah you know the amount of money you save in 50,000 miles of driving if you get 3% more MPG with higher pressure is about $100.00 if gas is $3.00 a gallon and you get about 40-45mpg. Is it worth the ride quality loss . . . hummmm I wonder. The tire wear should be a little less with higher pressure however but then you have the extra wear and tear on the suspension components from the hard drive. Makes me think a little . . . hummm.

Quote:hmmmmmmmmm svoboy i
 

Think it's like 60 each with a lifetime warranty for my car.