RL4R01A Transmission 1st to 2nd Upshift shock

[OE812]

I have an 02 Frontier with the KA24DE engine and RL4R01A transmission. Since I have owned it about a year, I have noticed abrupt and shock upshifts from 1st to 2nd. This happens when engine/trans is cold or hot. I have adjusted the shift cable to factory specs. Prior to the factory adjustment, it was shifting too early and causing truck to bog down but was shifting without the upshift shock.

I have done all of the required maintenance on the truck in accordance with the FSM. The engine has 177,000 miles on it and has the pesky P0400 code.

Please help me solve the upshift issue.

Jeff

[Towncivilian]

Is the fluid clear, bright red? Does it smell burnt at all? Have you ever done a transmission pan drop & filter change? How have you maintained the fluid exactly?

As for P0400, have you checked if the vacuum hose for the EGR valve is clogged or otherwise damaged? Have you ever cleaned the EGR valve?

I checked for TSBs for both this shift issue and your P0400 code but found nothing relevant.

[OE812]

Is the fluid clear, bright red? Does it smell burnt at all? Have you ever done a transmission pan drop & filter change? How have you maintained the fluid exactly?

As for P0400, have you checked if the vacuum hose for the <a href="http://motors.shop.ebay.com/Car-Truck-P ... =EGR+Valve" rel="nofollow" title="Link added by VigLink" class="vglnk"><span>EGR </span><span>valve</span></a> is clogged or otherwise damaged? Have you ever cleaned the <a href="http://motors.shop.ebay.com/Car-Truck-P ... =EGR+Valve" rel="nofollow" title="Link added by VigLink" class="vglnk"><span>EGR </span><span>valve</span></a>?

I checked for TSBs for both this shift issue and your P0400 code but found nothing relevant.

Yes, bright red clear. No burnt smell at all. I dropped the pan and changed the strainer about 18,000 miles ago.

EGR valve and manifold egr ports cleaned.

[Towncivilian]

What transmission fluid did you use during the service?

You could try adding a bottle of Lubegard Red. It's an additive well lauded by many transmission shops and vehicle owners. I put one bottle in my Pathfinders' RE4R01A-HD transmission and it has smoothed downshifts and shifts in/out of overdrive. It can generally be purchased at NAPA or Carquest for around $13 before tax. If you'd like more anecdotal evidence, see this thread.

Have you examined the EGR hoses for clogging, cracks, and cuts?

[OE812]

Thanks for the information I will try Lubegard Red. I have changed all of the egr hoses when I cleaned the EGR and Ports. I think the code may be the egr temp sensor but have to test the cold and hot temp. ohms