I think I have a Trans issue...

I have a 2008 Bighorn Ram with the 5.7. Over the weekend when it shifts into OD it feels like it is lugging or shuddering. Just started it all of a sudden. Does anybody know what is causing this issue.

My 2010 used to do that. They rebuilt the trans under warranty, lasted 40 miles before it started doing it again. They ended up getting a totally new trans for it under warranty.

That's probably not what you want to hear, but my experience.

Are you sure its shifting into overdrive or is it the lock-up converter you feel ? Because it sure sounds like a lock-up converter shudder. How does the trans fluid look ? I would also have it checked for codes as some models can set codes for converter problems and not turn the ck eng lite on as that depends on the code sometimes. I would also see if there are any TSB's that pertain to it. I do remember we had that problem on front wheel drive cars as the trans control module can bring the converter clutch in on partial lock-up which is like slipping the clutch and if the converter clutch is not burnished in right it can give a shudder. Some of the car models had a TSB where it reprogramed the trans module so it turned off the partial lock-up and it only had full on or off lock-up. Ron

I was driving down the road today and noticed when I put it in TOWING mode it did not do it and the RPMs were pretty close to what it is when everything is on. When I turned the OD off you could really tell the RPMs went up. I was also thinking it does it when the converter locked up. It acts like it locks up too early and then luggs.

Are you sure it's not an ignition misfire. When it shifts into overdrive , it really loads the engine and that is when you will get a secondary ignition related misfire ,plugs or coil being the most common.
It will feel like a shudder or fish bite under load.

I also posted on this question in the truck form.

Whenever you put the trans in Tow Haul or OD off it disables the MDS system so it doesn't drop cylinders to "help" fuel mileage.

I had an 08 and on my 11 mile commute my MPG didn't suffer any running in tow haul(no MDS) or regular.

The MDS was almost overactive on my 08, it would come on at low speeds even in my neighborhood. The MDS could sound like a miss at low RPM for sure but it should turn off when any load is applied(throttle).

First, Is the truck a 1500 or a 2500? A 2500 truck shouldn't have the MDS engine, they were only installed in the 1500 trucks and weren't recommended for towing anything large.

It is a 1500 and like Bad340fish said it stops doing it as soon as I puss the throttle any and when I turn on TOW hauling. I will be towing a 3000 lb race car on open trailer.

My son in law had a similar issue with his 10 Ram 1500 with the 5.7 MDS setup.

Turns out when he had his oil changed the place that did it put on a different oil filter, it was substantially smaller than what was called for. We changed the oil and filter and no problems since. They seem to be sensitive to that.

Dealership wanted to charge him $1200 you change out his phasor VVT solenoid and lifters, I believe. There was a TSB on this and step one was change oil and filter to ensure it's correct and retest. They didn't even try that.

But his issue did throw codes, do you have any?

If you haven't changed the oil yet it wouldn't hurt to do so just to make sure its got the proper 5W20 and proper filter.