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1989 Dodge Dakota Trans/Clutch Diagnosis (A535/NP2500)

135 views 8 replies 5 participants last post by  AC TC  
#1 ·
I was going to take the trans to a specialty shop for diagnosis but I wanted to run it by the wise folks here first - I've been burned at repair shops before and it's really a last resort thing for me now.

I'll describe what I've noticed and been able to reliably reproduce first, then talk about my suspicions and maybe you can help dial me in.

1. When driving at 35 mph, so the trans has a bit of rpm flowing through it, if shift into neutral, then from neutral slowly shift into first, I feel a force resisting the shift. I can push through it without much difficulty and as I'm pushing through it, the trans will make a mild lower pitched whine

2. As before, when the trans has some rpms glowing through it, if I press the clutch to the floor, there's a very short delay while the trans coasts down then I hear a faint rattle. Not like a broken metal rattle like, a rod bouncing around inside a bore just a bit too large for it.

3. If I'm in gear and coasting to a stop with the clutch fully depressed, as I coast there's a whine/whir from the transmission and if I put it into neutral (while stil coasting) it goes away

All of this is very mild, the resistance to the shift is easy enough to overcome with casual force and the noises are all so quiet that I can only hear them on smooth roads with no traffic around. I still want to get on this before it develops into a bigger problem though.

I bought the truck for $500 from a rural area outside of Charleston as a mechanic's special. No crank, no start, guy wanted it gone asap. I jumped on it and it was pretty bad, it had blown a piston. Still a good deal since it had every feature I wanted. I replaced the engine with a junkyard unit from the mid 90s and I recall having difficulty with getting the pilot bushing/bearing setup properly. Pretty sure it has a roller bearing in it, not a solid bushing like the 89 is supposed to have. So maybe the pilot bushing has gone bad either because I messed up the install or it's just not as compatible as I thought. It could also be that the clutch pack from the mid 90s is slightly different and maybe it's dragging under some conditions.

What do you think?
 
#2 ·
Sounds normal to me.
Except downshifting into first at 35 mph. Not recommended. That would put me through the windshield (if I didn't wear a seat belt).
 
owns 2011 Chrysler 200 Limited
#4 ·
First point...im impressed that you even can do it, its a 3.5 mph manouver at the most.
- have you checked the oil level?
 
#6 ·
I should have been more clear on the first point, I don't shift into first at 35, I coast down a fair bit before and during the slow shift.

I noticed today on my way out, that when I start the truck, the shifts are near effortless and as I drive the shifts have more and more resistance to them until they top out and stop getting more difficult. They're still relatively easy to shift, just noticeably more effort than when I first start the truck.

I'm more and more convinced that it's a problem in the clutch area. If the pilot bearing is wrong/bad then I bet when the trans/engine is cold, the friction acting on the input shaft is relatively small so the shifts are smooth. As the trans and engine heat up from use, I bet the metal expands and the friction becomes greater so the engine is still driving the input shaft a little bit even when the clutch is depressed. Does that make sense?

I dont think the clutch itself is dragging. When I fully depress the clutch pedal, and slowly release I can feel when/where in the clutch pedal travel it "bites" the trans.

Either way I need to pull the trans. While it's out, how would I be able to tell if the synchros are bad?
 
#7 ·
Definitely check the oil level and condition.
It does sound like the pilot bearing may be starting to wear out. If it were the throwout bearing, you might get symptoms such as grinding when shifting, or the vehicle trying to creep forward with the clutch in and a forward gear selected, at a stop; or when starting the engine.
 
owns 2011 Chrysler 200 Limited
#8 ·
If the clutch is starting to 'drag' when disengaged, it may be harder to shift into the lower gears.
At 26 years-old, the clutch hydraulics may be internally leaking down & warrant replacement.
Image
 
#9 ·
I think the temperature change causes the gear oil to thinnen and then the friction at the syncros gets lower and it will shift slower and harder.
- change the oil to a modern "syncro" gear oil.
This tranny should be safe for syntetic oil. Earlier trannys didnt shift good on syns since the syncros got to slippery