looking for opinions....
my buddy just bought a 99 1500 5.2 auto 4wd with about 110k miles, very clean. he only drove it around a little bit, got in a hurry and bought it. The reason this description is so vague is because its the best i can get out of him.

When cool, it drove and shifted fine. When it got warmed up good, and got up around 40-50 mph, the transmission started hammering. I can't get any better description from him, nor pin him down on whether its the OD shift or the TC lockup.

so, he takes it to a local mechanic for a fluid and filter change. According to mechanic, fluid very dark and old, likely the orginal. transmission was not flushed, VB not removed. just a simple fluid & filter change.

it immediately acts better and for 3 days the hammering goes away and it acts fine and shifts fine, although he says its a little harsh when shifting to OD. He drove about 100 miles in that 3 days. he also cheered up a lot.

then it comes back. hammering like a machine gun up around 40-45-50.

I understand that this removed only about 1/2 of the old fluid, but I assumed the new fluid and old fluid would mix together within about 25 miles, and it would then do whatever it was going to do at that 25 mile point and not wait so long (100 miles).

so, i'm asking 2 questions, feel free to comment on either one.
1. anyone recognize this, based upon my poor description ?
2. anyone have an opinion on why the problem would go away after fuild/filter for 3 days, and then come back.

thanks,
doug

 

Tell him to take it back and get The tranny FLUSHED, and run Royal purple through it. Yes, it is very expensive like 8 bucks a quart but worth every penny. Get it flushed quick and run this through it. Becuase he got it changed right, so now it has mixed and now he has gunk back in it, so by flushing it it will clean it. Get the gasket and filter changed with the flush. Run the royal purple. That is a really good place to start and that is really good oil. That should help


BNB

 

If its hammerin then don't waste 7+ a quart on Royal Purple, its not the fluid doing it, he has something wrong internally, sounds like torque converter or pump.

 

These are only my opinions.

If everything else has been ruled out as far as suspension,tires, loose cab mounts, etc...... and the fluid level is good in the tranny, here's are some things I have seen.

1. Something with the throttle position sensor, and the factory shift points. Has he enlarged the tires at all? Wouldn't stock be like a 245 or 265/75/16 ? That can wreak havoc. I had the same problem. The truck would get stuck between shifts. It would jump back and forth like you described. I have a 95 tho. We may have major differences. If it is the throttle position sensor, then your friend should be able to replicate the condition. My Ram had a sweet spot where if I held the throttle in the right place, everything would act up. A bad TPS can give the appearance that something major has gone wrong...lol. A TPS can APPEAR bad, if you have **** battery connections and bad grounds. Dodge Rams had LOUSY grounds in the mid 90's. That's a FACT. Some guys clean and re-calibrate their TPS and have great luck.

Something in the torque converter, could have let go and is obstructing flow. A valve body drop is not that big a deal, and a good way to see a little deeper in.



Remeber, Dodges have to be checked hot, IN NEUTRAL, level ground. If you need to do it cold just to make sure that fluid is present,...lol, then do it cold. Make it just up over the cross hatched area about 3/8 of an inch over the fill line.





If the hammering is not as fast paced,try notice when it happens. During a transmission upshift, downshift? Is it the torque converter locking then unlocking? One thing that can cause that effect is a bad, or dislodged, rear brake light switch. Sounds funny but if your brake pedal bobs back and forth, and "tickles" the switch, the TC will kick in and out. The cruise control will also disengage for no reason, or will be impossible to set. The switch is a poor setup, and the plunger only has so many cycles to it.

Check the rear output shaft for shuck. Check the yoke setup going into both axles. Sometimes that pinion nut that holds the yoke down, will come loose. I think they were never that tight from day one. Make sure axles are topped off, transfer case. Whatever.lol.


Ok, now, here's the EASIEST thing to do first. Go buy a new tranny temp sensor. Get in position, with a COLD tranny, and swap them out. If the previous owner towed, or abused the tranny, the temp sensor would have been damaged by temp extremes. That idiot light comes on at 220 or 230, I think. Don't quote me. What happens is, if that sensor isin't sending the proper voltage signals, the transmission will have adverse effects.

It sounds crazy but I swear that sensor could be doing it. If not, you said the fluid was old and dark. That's HEAT. Sounds like ya got something going on somewhere............lol. I could be very wrong.

I hope it's a minor thing. You'll need the money for upgrades after you catch the virus we already caught. LOL


Good luck

 

Try a stall test.

 

I did a stall test at Outback Steakhouse last night.


Good help the two women who were seated closest to the men's room.....[sm=badidea.gif][sm=escape.gif].lol

 

uummm. what's a stall test ?

 

These transmissions have an electronically modulated torque converter clutch apply.
I have done a lot of research and found that SHUDDERGAURD is the most simple fix. When the fluid gets old, it loses some of the qualities that help keep the converter from shuddering. Shuddergaurd replenishes those additives.
Give it a try. It is not very expensive.

 

ok, proceeding with thoughts as follows. original hammering assoicated with old, used up fluid. first change introduced about 1/2 the volume of new fluid with the old. new fluid and remaining old fluid mixed together withing 25 miles or so. all still well so far with this mix - no hammering.

new fluid contains lots of nice new detergents that start working on all the old built up sludge. after about 100 miles, enough old sludge is worked loose to overcome the nice new fluid, and the problem returns. at this point, new fluid may be even dirtier than the original, since all the old deposits may be in motion.

will proceed with one, or even 2 more fluid and filter changes, unless local mechanic can pick up on any electronic codes.

thanks for the opinions, keep em coming.

 

Ok, here is my opinion. I would follow these other guys advice with flushing the fluid and hope for the best. My opinion is that any loud "hammering" noise coming from the tranny is bad news. Changing the fluid out may mask the real problem for a while - but chances are that there is some kind of internal damage that eventually will leave you sitting somewhere. Try the fluid flush, but keep on the lookout for a more permanent fix - (good tranny shop, tranny from salvage yard, rebuilt tranny, etc.) Keep in mind also that if the converter goes bad it usually takes the tranny out with it. Happened to me twice.

Also - do you know if there was any metal in the tranny pan the first time the fluid got changed? If there we metal pieces or flakes in the pan, that would further back up my opinion.....