Rough Downshift After Coming To a Stop

I have a 95 tacoma that seems like its downshifting hard after moving from a complete stop if that makes sense? So lets say I come to a complete stop at a red light, when the light turns green, theres a noticeable thud and a slight jerk when I let go of the brakes to start moving forward. It doesn't happen ever single time but it doesn't rarely happen either. Anyone experience this and was able to fix the issue? BTW it is automatic transmission. TIA

 

Axle wrap

 

Heard of it before but don't know much about it. Any details and how to fix it?

 

Greasing the u-joints on the driveshaft sometimes helps, either have the service dept do it or you can do it yourself, it's really easy. Just need a grease gun and some grease from the local auto parts store.

 

If it only "sometimes" helps is there any other solution if the issue keeps occurring or is it a permanent problem? Will definitely give greasing the u-joints a try though.

 

Weak leafs are causing the axle to "twist" when accelerating or braking. Suddenly releasing that tension will often cause a thud or jerk.

At a stop the truck is already in gear and power is being transferred to the axle. That would rule out driveline slop (most of the time) because the slop has already been taken up.

 

would a better but more costly solution was replace the entire leaf spring?

 

There are several threads on here that discuss solutions to axle wrap. Things I've read that people have done to combat it are: new leaf springs, leaf spring helpers, or traction bars.

Here's the thread on the helper spring mod.
https://www.tacomaworld.com/threads/goodbye-axle-wrap-mod.108316/

 

Not at all. Vehicle is already in first gear when stopped in D. So it doesn't downshift when you start moving. It will upshift when you get to the right RPM

I agree with others that it's likely not trans related. But regardless.............

Is the trans properly filled? Is the fluid still a nice reddish pink, and smell like fluid from the bottle, or does it have a burnt odor? When was the last time the transmission was serviced? It's 22 years old with ???k miles. It deserves some love.

 

Replacing the rear springs probably won't solve your problem. I recently installed a complete OME with Dakars on my 2000 pre runner and, while the ride improved, axle wrap was not significantly improved.

 

My 97 manual was doing this even after new leaf install until I changed the rear u joint.

 

Grease the slip yoke

 

This.
This video is what I did, and it worked: https://www.youtube.com/watch?v=Jyltxe2nPEg

 

An auto wont do that because of a u joint since theres constant force taking up any slack in that situation.

 

Maybe you're correct but I think it would depend on the amount of slop in the joint as well as the function of additional torque being supplied be pushing on the accelerator pedal. While my 5-speed technically still had resistance applied to it while driving down the highway if I let of the accelerator it would vibrate then clunk when I pushed the accelerator back down.

 

Yea but this is goin from a stop.

 

I understand but I am trying to understand how it is different. There is still a relaxation of torque from release of the accelerator and then there is a torque multiplier from the stop by pushing the accelerator. Perhaps I am just dense but I do not understand how it would be impossible for it to be a u joint but not the slip yoke as both would have the same constant pressure you are referring to since it is an auto, correct.? I am in no way saying this is his issue, just a suggestion.

 

Slip yoke thud is usually caused by it sticking not because of there being actual slop between the spines. say when braking the rear axle gets pulled back some pulling out the slip yoke. it can then get stuck in that position with force being preloaded by the leafs. when accelerating the yoke frees up and the axle jolts forward some causing a thud/clunk. this is amplified with axle wrap.

 

Sounds like axle wrap caused by weak springs. Try the u bolt mod. Even after I bought brand new General Springs I still got wrap after a few months.
Ended up going with the u bolt mod and it's gone...

 

Got it, thank you