1999 RR 4.0 Gems with 190k miles.
Just started to vibrate / sudder under acceleration.
Engine mount? CV joint? How do I diagnose this?
There is also a bird-like chirping at same time.
All ideas welcome, thanks.

kevin@dokdoc.com
612 709 2221

 

At those miles, my guess would be the transfer case chain slipping. However, you won't know until the sound is pin-pointed? Do you have an idea where it might be coming from?

 

Thanks but my mechanic figured it out. A bad front U-joint. Replaced it and all is well for $230. Now, about this downshift issue. Can it be adjusted? Is vacuum system involved?
Thanks.
kevin@dokdoc.com
612 709 2221 texts

 

Glad to hear that is all it was. I recently had that issue on my Discovery, it would only do it when pressing the gas and when it was going over 30mph.

Down shift issue? Please explain.

 

Here's what happened. I replaced the cylinder head gaskets (myself! An amateur), then put in a new radiator. Car runs great. But since that repair, it does not want to downshift (kickdown?) when I'm going, say, 55mph in Drive - it won't kick down to 3rd. It MUST be related to the work I did. Could it be a vacuum leak? Is there a "switch" under the gas pedal? Something else? Car shifts manually just fine, although I don't want to be driving like that. In "sport" mode - no detectable change. Thanks for any and all help.
kevin@dokdoc.com
Minneapolis
612 709 2221

 

The FSM says on page 21 of section 19 that a bad throttle position sensor can cause poor acceleration and loss of kick down. Just a thought.