Can't get into second gear when down shifting...

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
dinof
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Re: Can't get into second gear when down shifting...

Post by dinof » Sat Jan 31, 2015 6:24 am

Wolfman wrote:Here is a trick for you, Dino.
When stopped and shifting to first or reverse, push the clutch pedal down and shift to second or third first. This stops all the moving parts that need to stop and no Tap Tap when going into first or reverse. Your tranny will love you for it !

I would consider this but as you have seen what situation I had with Mr. 3rd gear, I may not want to use my sycncrho assembly any more than I have to! :(

Perhaps when I muster up more courage and feel my situation is totally gone, I will give it a try.

Thanks,
Dino F.
Dino Falabrino
On the "G" since 1998.
1943 GPW 102310 DOD 3-3-43
1928 Model A Roadster Pickup
1930 Model A Tudor
1968 Taco Minibike


Wolfman
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Re: Can't get into second gear when down shifting...

Post by Wolfman » Sat Jan 31, 2015 6:36 am

The good thing on an L head jeep engine, when you overspeed and float the valves, you don't have to worry about making valve contact with the pistons and bending a valves. 8)
The trick I mentioned won't cause your synchros any grief. Everything should be down to idle speed.
Of course, this is if the clutch is not dragging. That might up the ante.
Mike Wolford
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AOPA ( 50 yrs)
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4th Inf. Div. - 5th Inf. Div. - 2nd Armor Div. - CIB

bazza46
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Re: Can't get into second gear when down shifting...

Post by bazza46 » Sat Jan 31, 2015 11:36 am

Usually a dragging clutch doesn't make any noise. Do you perhaps hear the 'rattling' sound some jeep clutches make when disengaged ith the engine running? That isn't detrimental to gear changing.

Wolfman's suggestion about trying to shift into first or reverse when stopped is a good idea to establish or not whether your problem is caused by the clutch dragging.
If there's no crunch when shifting into first immediately after depressing the clutch, then the clutch isn't dragging.

If that's the case, your problem lies elsewhere. Maybe the three synchro plates on the synchro collar (drum) are partly popping out of position, jamming the drum, and when you stop, the torque is removed from the unit, allowing them to click under the drum and allow it to move.

Also, the circular spring that pushes out the synchro plates, if it is installed incorrectly, with one end protruding instead of being tucked up under the synchro plate, can work loose and jam the synchro drum when shifting.

If nothing else is suggested, I'd remove the top of the transmission and check the condition and position of the plates and synchro drum. Push it into 2nd and 3rd gear with a screwdriver or metal rod and try to see if all goes smoothly. If the ends stick up before being pushed down, there may be a problem there There have been several lengths of plate circulating recently; some shorter and some longer I believe. They sometimes work O.K. but other times they jam.

Just my thoughts
"The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt"..Bertrand Russell

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kdmann143
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Re: Can't get into second gear when down shifting...

Post by kdmann143 » Sat Jan 31, 2015 1:12 pm

Hi
I had same shifting problem 3rd to 2nd last year.
I recall now my problem started after I slowndown
My jeep by shifting in 2nd gear at high speed.
My transmission was completely rebuilt and worked perfect before.

Only way to shift from 3rd to 2nd was to press clutch halfway and
Reving engine at bit and then shift same time.
Then shift.

Well I rebuilt my transmission again and used new synchro rings and 2nd gear,
The problem then went away.
I prefer never try to slow down jeep at higher by shifting into 2nd now.
May be downhill but not approaching trafic lights.

Also to mention the synchro rings I replaced had mirror wear.
1942 GPW
1943 Gpw
1943 GPW Radio Jeep USMC 48649
1942 Slat grill
1943 Bantam trailer

44 MB sold
42 CDLV sold
45 Gpw sold
45 gpw sold
1950 M100 sold


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