PDA

View Full Version : Rough downshift bumping



claylong
07/19/2009, 12:50 PM
I test drove a VX recently, and I noticed some rough downshifting. Not sure between what gears it occurs, but it's just before coming to a stop, so it was probably low gears and might also have something to do with the torque converter, not sure.

The "roughness" comes in the form of a bump / jerk that can be felt pretty clearly. It's not BAD, but noticeable. The bump seems to be coming from the front half of the VX. I drive a honda normally, so I am not sure if the bump is just front driving something a little more rugged or not.

I ask you, could a downshift bump be a problem, or is it just the VX drive train doing its thing?

SilverBullet75
07/19/2009, 05:10 PM
Strong possibility... search for "mode switch"
You may find your answer there... :)

WILLY
07/19/2009, 06:51 PM
sounds like low trans fluid to me.

claylong
07/19/2009, 08:26 PM
You guys seem to be pointing me in the right direction. I couldn't think of other ways to describe what the problem FELT like, so my searches were turning up unrelated threads. "Jerking" or "slamming" should have been the words I used.

Thank you!

tom4bren
07/20/2009, 05:01 AM
You didn't mention if it happened every time you came to a stop. If it only happens sporatically, the AC compressor could just be kicking on at the most inopportune time. That would accelerate the engine while it's trying to downshift. It won't damage anything but it is bothersome when it happens.

Remember to keep your foot firmly on the brake while stopped. Several members have posted near fender benders because the VX will start creeping forward when the compressor kicks on.

JAMAS
07/20/2009, 05:23 AM
The search term you want is....."Clunk" ....

and it sounds like it is just the normal clunk noise that a lot of us have had as we come to a stop. I believe the proper term is driveline lash.

Lube up the u-joint and the yoke on the driveline. That helps alot.

A tranny flush in combo with that may help as well.

Clunk TSB (http://www.drivehq.com/file/df.aspx/publish/mgpa/kaats/clunk.gif)

vt_maverick
07/20/2009, 07:14 AM
Also could be the TOD / 4H disengaging when you drop below 15 mph (I think)...

nfpgasmask
07/20/2009, 08:41 AM
I say mode switch or you need to do a complete tranny service.

Bart

claylong
07/20/2009, 09:53 AM
You didn't mention if it happened every time you came to a stop. If it only happens sporatically, the AC compressor could just be kicking on at the most inopportune time. That would accelerate the engine while it's trying to downshift. It won't damage anything but it is bothersome when it happens.

It did NOT happen every time I stopped. I have drive vehicles with the compressor kick, but I am pretty sure that what I heard/felt was more intense than what the AC could do. So I am starting to think it might actually be mode switch or transmission fluid level / service.

FYI - This is a VX I am looking to purchase, and noticed the problem during a short test drive. I think the combination of louder exhaust, rough road, and the "clunk" left me with the feeling that the ride was somewhat more rugged than the other VX's I have driven. I'm trying to decide if all of this put together is telling me to stay away from this VX, despite it's color and low miles. :)

Thanks for all of your tips, guys!

vt_maverick
07/20/2009, 11:22 AM
Sounds like you should steer clear to me. Seems like VX's in all colors are popping up weekly on eBay and AutoTrader now.

Marlin
07/20/2009, 02:41 PM
I thought all VXs made that sound? Mine does, and drive the piss out of it, on and off road. :rolleyes:

Riff Raff
07/20/2009, 02:58 PM
I say mode switch or you need to do a complete tranny service.

Bart

I agree that it may simply be a "mode" switch. Please check and verify both Winter Mode and Power Mode buttons are in the "UP" (off) position on the center console. In addition; a complete tranny service would be recommended, as all vehicles are happier with fresh lubricants and filters.