[94bobgt]

The car runs and drives beautifully when on the accelerator, but moving slow the car shutters violently when shifting gears. It is intermittent, I have flushed the transmission, checked U-joints and rear end Lube. The overdrive button works and kicks in fine. Just curious if anybody else has this problem or had. It has set for a while. I just acquired the 94 GT convertible that my sister bought new. She passed in 2005 and my niece has had it sitting in the garage since. I just gave her 5K for it and has 79,000 MI.

 

[Dwain]

It sounds like it could be a pressure related problem in the trans based on what youre saying. When you go WOT, the ecu calls for higher line pressures. When cruising, it drops pressure. You may be experiencing a slipping when cruising that is possibly causing the shudder. Can you describe in more detail exactly what is happening. Does the rpm seem to bounce around a lot when its happening?

 

[94bobgt]

It sounds like it could be a pressure related problem in the trans based on what youre saying. When you go WOT, the ecu calls for higher line pressures. When cruising, it drops pressure. You may be experiencing a slipping when cruising that is possibly causing the shudder. Can you describe in more detail exactly what is happening. Does the rpm seem to bounce around a lot when its happening?

You were right on the pressure related, took it to a shop and they did a high pressure flush on the transmission, I just did it myself at home. After that everything's fine now. Too much garage time, they don't like that. Haha

 

[94bobgt]

Thanks for your reply Dwain!

 

[SNK VNM]

Probably unrelated but, in a 95 F150 5.0 4R70, 110k miles I had something somewhat similar. Under acceleration the truck drove and shifted perfect. Cruising on the highway or any speed in OD there would be a shutter that came and went. Only happened in OD while cruising. Long story short the od band was toast and the others weren't exactly great shape. Had it rebuilt and reinstalled. Problem solved. The rebuilder mentioned he'd seen a few aode/4r70 trans with the same issue, typically in trucks.

 

[Wmac]

Probably torque converter shutter. Seems to happen to most aode and some 4rw70 trans and at around 60 to 80k miles. First happens at cruising speeds just before the 2-3 shift or 3-4 shift. Use mercon V only and add a tube of Lubegard Dr tyranny shutter fix. Also consider a big ass stacked plate aux cooler. (and a jmod)

Worked for me.

 

[94bobgt]

Thanks for your reply Wmac.
Flush with a new filter and fluid worked for me, but I will take your advice & add both Lubegard Dr tyranny... thanks again.

 

[CDW6212R]

The Lubegard is great stuff, but at this age it's about time to replace some small items. The solenoids and accumulators are prone to be part of symptoms that occur at 20 years etc. If you get any issues that seem more than minor, avoid driving it until you can have something more done. Most rebuilds happen after a minor issue turns bigger, but people then keep driving it until it won't move. Sp pay close attention to how it shifts all the time.