B2 Rear Wheel Lockup while Downshifting
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B2 Rear Wheel Lockup while Downshifting
Has anyone ever experienced the rear wheels of your B2 locking while downshifting your manual transmission from highway speed? This is a 1987 B2 XLT. Transmission has been gone through. Cannot isolate where the trouble might be.
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From: Yokosuka, Honshu, Japan
Are you downshifting at too high of a rate of speed for the gear you are downshifting into???????? If you have the owner's manual, it should tell you in there what the maximum speeds are for downshifting, and I can't remember if it's on the driver's side visor as well. I'm going to guesstimate here, but I believe the numbers are something like this: 4th - 40/45, 3rd 30/35, 2nd 20/25 1st 5/10. These could be a tad on the high side, but close to what the numbers are in the owner's manual (and generally speaking close to the numbers for ANY 5-speed transmission equipped car or truck). If you actually get the transmission to shift into a lower gear at too high of a rate of speed and release the clutch, the rear wheels will lock up or "chirp". This is also bad for the driveshaft, rear axle / differential, as well as the clutch and transmission / t-case, especially the tranny because you can damage synchros and gears.
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From: Rio Rancho NM
B2 trannies are not that strong. Ask me how I know! If you're downshifting hard enough to lock up your rear end you are abusing your driveline. A B2 is not a sports car and shouldn't be driven like one. Use your brakes and save your clutch, tranny, t-case, ujoints, etc. It's a lot cheaper to replace brake pads/shoes than driveline parts.
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From: Yokosuka, Honshu, Japan
Exactly where I was going, powr... I've seen what happens when you blow gears/synchros/bearings in a manual transmission... it's UGLY. Not to mention, if his rig has that crappy GKN junk of a rear driveshaft... those things don't handle a whole lot, either. Okay, just for fun, I'll ask... How do you know, powr? 
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From: Rio Rancho NM
Originally Posted by kernel-panic
Okay, just for fun, I'll ask... How do you know, powr?
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B2 Rear Wheel Lockup while
this seems to be a complete mechanical lockup and not an engine compression rear wheel chirp. The engine actually stops (engine lights come on) until i quick depress the clutch and the engine continues. Once the clutch is release everything is fine. I can continue. in some cases the engine has comepletely stopped. i was thinking something more in transfer case. but i am at a total loss.
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From: Rio Rancho NM
Sounds to me like you have good compression. Are you trying to blow your engine or toast your driveline? If I were you I would stop downshifting like that. Seems like it runs fine so stop downshifting and don't worry about it. Why do you need to be downshifting? You are trying to drive it in a way for which it was not designed. You're only asking for major trouble if you continue downshifting. One thing that comes to mind - you're not shifting your t-case into low range are you? We're talking explosion if that's what you're doing.
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When i downshift, it's not that I'm using the engine compression to slow myself down, I'm downshifting so that i can continue moving at a lower speed. Like when leaving the highway and and i need to make a turn at the end of an offramp where i have not completely stopped. it is difficult to continue a turn at 15 mph in 5th gear. I'm just trying to use the correct gear for the speed that I'm moving at.
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From: Yokosuka, Honshu, Japan
Uh, you're not giving it enough gas to keep the engine running and/or letting off the clutch too quickly or like we've already said... downshifting at the WRONG speed into the WRONG gear? Sounds like you need a little more practice driving a manual transmission.... 
EDIT: UH, you're not shifting all the way down into 1st gear are you??? You'll eat the transmission, or rather, it will grenade if you keep doing that. 2nd is plenty far down for 15 mph.
EDIT: UH, you're not shifting all the way down into 1st gear are you??? You'll eat the transmission, or rather, it will grenade if you keep doing that. 2nd is plenty far down for 15 mph.
Last edited by kernel-panic; Apr 13, 2007 at 12:10 AM.
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jdhv - THANK YOU!!!!! I just found a trans shop that seemed to have experience with B2s, his comment was similar, a bent shift fork. Not fully disengaging the previous gear causing two gears to mesh and bind due to the ratios.
I've built quite a few offroaders with standard transmissions over the years, this is my first B2 and I knew it had nothing to do with the way i was driving it. Thanks again!
I've built quite a few offroaders with standard transmissions over the years, this is my first B2 and I knew it had nothing to do with the way i was driving it. Thanks again!
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From: Yokosuka, Honshu, Japan
Also, another notable problem with pre-M5OD transmissions is the shifter. My '86 Ranger would jump in and out of gear and sometimes I couldn't even shift, and it did the lock-up thing once. Found out the shifter had lost some parts, so... ended up eventually replacing it, but drove it for the longest time with an 'engineered fix'.
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