Deuce engine vibration

[peppy]

So recently my deuce (1971 M35a2 w/multifuel) has developed an moderate engine vibration (you can't feel it that much but you can hear it) right around 1500 rpm (in any gear), no vibration before or after just in that very specific rpm range, engine runs good idles smoothly and doesnt smoke on startup, fluids are all up, anyone have any suggestions?

 

[Clay James]

If a deuce is not vibrating or rattling it's not running.

 

[RAYZER]

If the vibration occurs while in gear,check all of your drive shaft flange bolts.

 

[gotojw]

Hello. I noticed it's an old thread but wondered what the outcome was. I've read about a dozen threads so far. I've checked in gear out of gear transmission in neutral transfer in neutral low high all combinations I could think of. Always a very loud noise at rpm range 1700 to 1900 or so and then smooths out before and after that range. Checked drivelines, but because this happens even when clutch is no running gear engaged I assume it must be engine or something else. The sound is like someone started up a monster chainsaw under the hood and let her rip. Along with sound is vibration. I checked and replaced fuel filters. The primary was all kinds of bad! Which during that adventure I realized that I had a longer secondary 10 micron filter installed in that primary housing. No spring no small filter. I did replace with a clean 10 micron full length filter. I have noticed a ticking sound from the top of the motor close to the cab end of the engine. Sounds like a very loud air ping... clicking type sound? Hard to explain... old pressure is 60 when driving down the road... drops to 15ish after warmup and at idle. Any thoughts... or additional questions for me? Also, just want to say this forum is AWESOME! I am happily amazed with all the content and cool people on here! Got my deuce a month ago and just barely getting her rolling. Front boots were trashed, so got the zippers, but figured best to tear it down this first time. Also planning an electric power assist steering setup... pulled the parts off a pick a part vehicle. I think it will work decently with just a little assist. I'll be posting that as it progresses.

 

[gimpyrobb]

Have you checked the belt on the air compressor? It could be the governor too.

The primary filter is there to catch big crud and let water settle out, it is SUPPOSED to be shorter than the others.

If your worried about the oil pressure, remove the sending unit and put in a mechanical gauge to verify pressures.

 

[gotojw]

Hello gimpyrobb. Thanks for the eesponse. I have read much of your postings across the deuce threads so far. I fell I have checked the air compressor belt, but will check that and the governor also. I locked the throttle at the troubled rpm and checked up at the front and sides of the truck engine bay. (A very uncomfortable place to be around with that much engine revving away! Haha... probably should ad wheels chocked, tranny and transfer case inneutral). The sound seems to be coming from the front area of the engine, but it is very hard to tell because there is a lot of noise. I wonder if noise c I uld be coming from the fan assembly? Thanks again for the comments. I will check the belts and governor. And report back. Ps. Any links for getting the spring and other hardware I need for that primary fuel filter? I have a shorter wix filter, but no spring for it or anything g else it may have required originally.... last thought was getting some spin on filter sets for oil and fuel. Thanks again.

 

[rustystud]

Have you checked the belt on the air compressor? It could be the governor too.

The primary filter is there to catch big crud and let water settle out, it is SUPPOSED to be shorter than the others.

If your worried about the oil pressure, remove the sending unit and put in a mechanical gauge to verify pressures.

I totally agree about the air-compressor belt ! Mine just started doing this yesterday and I found the belt was loose and "flopping" all around. I didn't tighten up the set bolt on the compressor enough when I replaced the belt the other day.

 

[gotojw]

Will be checking it first thing after work! I think I have a problem, It's taking all my free time and cutting in to time for other things.... hahaha

 

[gimpyrobb]

The other thing is to see what happens when the air compressor kicks in. Some times the belt will not flop(as much) till the air gov turns on the air compressor. I would think you could take the belts off the alt to check if the noise is from the fan assembly. I had a fan decide to shed one of its blades while driving down the road. It took out my radiator, might not be a bad idea to inspect it.

 

[gotojw]

Hi. Got off work and rushed home to tinker a bit! The fan blades are solid, very sturdy. The belts are all tight the seem to have very little depression. I tried to wiggle fan blade bully and air compressor pulley... no play. I did have to remove and research the gasket on the primary fuel filter. I noticed that it was dripping fuel. Good news is the fuel pump in tank is working, I removed fuel cap and heard fuel being agitated. Now I think I've developed a fuel leak near the fittings by the piece next to the power steering pump. Will get into that when the sun is up tomorrow. I am really interested in switching to spin on type filters. I have a brand new racor spin on water separator filter system that is heated.... although I probably wouldn't setup the heat. I don't recall the model of the racor, but it is similar in size to the canisters of the secondary filters. The hunt goes on for the rattle at 1800rpm? I will attempt valve adjustments this weekend. Got the tm's downloaded, will search through them to find which one covers valve adjustments. Briefly looked through earlier, lots of great info and pics! Any thoughts on racor filter?

 

[rustystud]

Did you actually run the engine and look at the belts ? Mine checks out fine if you just do the finger test, but when it's running you can see the belt flopping.
Remember your trying to "recreate" the problem and the problem only happens when the engine is running.

 

[gimpyrobb]

Did you actually run the engine and look at the belts ? Mine checks out fine if you just do the finger test, but when it's running you can see the belt flopping.
Remember your trying to "recreate" the problem and the problem only happens when the engine is running.

See post #6.

 

[gotojw]

So I visually inspected this morning. No flop in the belts. The parker racor filter assembly I have is a r120t. Looking online it appears to be for a tractor. It's much larger filter, but will thereceive be enough pressure sent from the in tank pump to push the fuel through? It's a 10 micron filter, but I am wondering if microns don't matter when it comes to how much pressure it takes to get fuel through? I read an interesting article last night about fuel filtering vs fuel polishing? Says filtering can remove combustible btu materials? Polishing apparently uses a centrifuge in addition. It was a marine boat article. Any thoughts on this?

 

[gimpyrobb]

Honestly, I think your too worried about it. I run a stock primary, stock(1st) secondary, and a 6 micron final filter. Other than running alternative fuels, I have never had to change filters from pump diesel.

If your running alt fuels, filter it before it goes in your tank and you'll be fine.

 

[rustystud]

See post #6.

I though it read as he was by the truck side but not inside the engine compartment. So since he posted that he visually checked them in "post 13" I think I read it right. Maybe not.

 

[RAYZER]

You could try running the engine with all belts removed to see if the noise goes away, keep an eye on your engine temp.

Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[m715]

I had something like this happen to one of my trucks,took a while to pinpoint. Look at your raidator housing coming unsolderd under the filler neck. Also the lower rad metal housing for stress cracks.

 

[m715]

wanted to add to above,my lower rad housing cracked and rubbed on the crank pulley I forget the rpm range but it made a heck of a racket.

 

[gotojw]

I have noticed that one of the radiator columns is detached from the rest of the radiator?!?! I had no idea that was possible without leaks everywhere? I have check over many bolts for tightness. I have not removed belts and ran. Will try that. I guess I could wedge something between the radiator and broken piece? Luckily it is one column of radiator on the end... so possibly something wedged on outside of radiator and the broken piece will help. I see a guy has a radiator for sale here on craigslist. Had a cab for 400 that I was gonna try and get for making crew cab, but that sold! Haha. Belts and radiator I will check. I noticed the vented shields under the wheel wells really don't seem that secure passenger side flops all over, but checking this during running doesn't seem like sound comes from it. I have been reading threads in valve adjustment... want to do that soon. I've done this on my old diesel Mercedes so think I can probably do it right on this. Have the special gapped tool already. But if I could find someone in my area to do it correctly I would likely take it to them. Lots of great info on this forum. It's very cool to find people willing to share wisdom and knowledge about this stuff. Seems this day most people don't want to help anyone without a charge! Cool people on here. Thanks!

 

[gimpyrobb]

You haven't received our bill in the mail yet huh?


























Hahaha!