Hi guys any help will be appreciated and probably save my marriage...
I just purchased a 1995 ram van SLT, 318 engine, 3 spd auto transmission (no od) bought the van specifically to tow my 23' boat, about 3400 lbs with trailer. Test drive went well, engine sounds fine, power seemed adequate, van has 142k miles and seemed overall in very good shape.

I brought the van home, hooked up my trailer, went to marina, backed trailer in, loaded boat - van would not pull boat out of water... Transmission does not seem to be slipping, just like the engine didn't have enough torque to pull it out. Almost like tranny was in 2nd gear. I manually selected 1st, did not matter, I also notice a similar issue in reverse. Has no reverse torque, full gas petal would not spin a tire on gravel...

Van seems to run fine on the road, not overloaded with power but seems about normal. Can run 65-70 with no issues, transmission seems to shift fine, no hesitation or slipping.

Any thoughts are appreciated...

 

I sounds like the tranny is slipping. I have 115K on mine and I just had my 3-speed rebuilt. This is just a guess though...

 

More information? when the van failed to pull the boat up the ramp
did the engine rev, bog or misfire while you were pulling.

With the info you to gave I could not really help but a slipping tranny
maybe the problem.

 

Well, I don't have a tach but it sounds like the engine is revving to about 2000 maybe 2500, it is acting like the torque converter is locking up and the engine just does not have the power... Could I have a clogged catalytic converter? Check engine light works but is not on with engine running. Any way to check cat convertor without removing it?

 

Ok, checked cat convertor, drilled small holes before and after - slight amount of back pressure but not too bad, don't think it's clogged

 

Checked exhaust back pressure before and after cat converter did not bump the needle, vacuum holds steady at 15.5" if I goose the engine, vacuum drops very slightly, if I put in gear and "power brake" at full throttle vacuum drops to zero, max rpm is probably about 2k seems like torque convertor and trans acting normally

 

Well you may be on the correct track thinking the tranny is slipping. Now
a 5.2 in first gear (on any boat ramp I have used) @ 2000-2500 rpm has
plenty of power to move 3500lbs.

I can not understand how you explained driving without the trailer is normal
but then it can not pull 3500lbs up a slight grade @ a couple mph.

Dumb question but are you sure your wheel(s) were not spinning?(low traction)

I must say this is strange.

 

Drop the tranny pan, perform a band adjustment on both the low/reverse band and the intermediate band. Replace the filter and fill the fluid to the proper level.

 

@ IODJ44, wheels were not slipping, engine was just groaning - just as if I were holding brake & gas.

Without the boat on the trailer the van did go up the ramp but it really lacked power - full throttle and it creeped out at 2 or 3 mph - again it did not sound like tranny was slipping, it just acts as if the engine has no power.

@Alloro if bands needed adjustment would the engine still be bogging down like its under very heavy load? As an example if I floor it on a gravel road engine does not rev up it just starts slowly accelerating not enough low end power to spin a wheel. However once up to speed it seems ok, can set cruise @ 65 and it maintains. It is acting just like I have the power of a 4 cylinder engine

Engine starts fine, oil pressure is good even at idle and warm, engine is not overheating, no stalling, sputtering, misfiring, pinging or spark knock. My next step is to verify good fuel pressure but I have to go buy pressure gauge, also seems like most people experience hard starting when fuel pressure is low.

Thank you both for your insight, any other thoughts are very appreciated.

 

@alloro - please excuse stupid questions I have not had a bunch of experience with slipping trannys. If the tranny is slipping would the engine rev way up or would the torque convertor still lock up and put a load on the engine? If I were compare how the van is acting while "power braking" it acts the same (rpm wise) as if I were to do the same thing in my Camry.