Strange Popping Noise Under Load

[rickf]

I have been following this from the beginning and he has been quite clear about what he has done and removing the rear drive shaft will eliminate any possibility of a load related noise coming from the rear. Unless someone can explain to me how the power is getting to the rear differential without the driveshaft. I also agree that the problem started after the locker install but he also did a lot of other work at the same time. I pointed out that people did not read the original post and it was pointed out to me that the most pertinent information was in post number 2. So I will say go back and read BOTH post 1 and 2 and then think a little before jumping on this man. I think he has done a very good job of explaining what he has done and he covered a LOT more bases and did a lot more diagnosis than most who come on here and say "What is this noise". Most have done nothing at all.

 

[wheelspinner]

The axles still spin the differential EVEN WITHOUT A DRIVESHAFT. He pulled a single axle but not both. A single axle pull is not sufficient to isolate a locker. It will still be driven by the axles regardless of whether the drive shaft is in.

 

[Jeepsinker]

If not the locker, then it could be some worn teeth or bad dogs in the transmission, worn/ stretched jackshaft splines, worn teeth in the transfer case, transfer case air solenoid tryin to partially engage the front drive but failing to go all the way in or out.... Really there is no way for any of us to tell without being there and looking at the truck for ourselves, so what more are we supposed to offer here? I've done my best and offered all I have in this post and my others. A least we can say it isn't the from or rear driveshaft splines slipping. That leaves trans, jackshaft splines slipping, or transfer case.

 

[rickf]

If there is NO DRIVE SHAFT then how is the rear differential getting a load? It only happens under load and it IS happening WITHOUT the drive shaft in? How is the load being transferred to the rear? It is not so that eliminates that. I know what you are talking about with the dogs catching and binding but this is not his problem.

 

[rustystud]

If there is NO DRIVE SHAFT then how is the rear differential getting a load? It only happens under load and it IS happening WITHOUT the drive shaft in? How is the load being transferred to the rear? It is not so that eliminates that. I know what you are talking about with the dogs catching and binding but this is not his problem.

Actually he said it "it happens more under load" . The only time it doesn't happen is when he is coasting. Now chigger , when your coasting are you using your brakes at all ? or just flying on down the hill ? The reason I'm asking is that the differential will experience different loads depending on the force against the wheels, which transmit through the axles. Again, it would be best if you totally eliminated the rear differential from the equation. Just as a FYI, when you say you have only one "axle" that does not mean only one "differential". It threw me for awhile after reading it . "How does he drive with just one axle in back ? " . There is one thing that I'm wondering about. When you rebuilt the transfer case, did you do it or did some shop do it ? The reason for my question is if some shop repaired it did they use the correct gears or did they substitute some gears from a non air-shift unit (Sprag) ?

 

[chigger]

Update,

I was driving the truck on Friday and out of the blue, the truck suddenly doesn’t want to shift to 3rd. To get to third, I have to wind out 2nd before shifting. I can’t get it into 3rd on downshift. The truck does not slip out of 3rd. Also there is a loud squeak when allowing the truck torque to decelerate the truck while in 3rd. I checked the magnet drain plug and no metal. On Saturday, the 5th gear suddenly does not stay in gear.
On Sunday, I pulled the top cover of the transmission off, Removed the output seal and bearing and pulled the output shaft gear set. I found the retaining clip for 5th gear was broken and I recovered all the pieces. 5th gear was allowed to walk forward on the shaft towards the 4/5 synchronizer. The brass synchronizer ring that mates with the conical part of the 5th gear is completely worn out. I assume it is from 5th rubbing against the synchronizer all the time since the C-clip broke. Inside the 5th gear is a polished steel bushing (bearing) that has a dowel pin to prevent the bushing from spinning on the shaft. The dowel pin came out and allowed the bushing to spin on the shaft. There doesn’t appear to be any damage to the shaft or the bushing. The dowel pin has some damage.

When I replaced the 5th gear on the counter shaft on 11/23/14, I inspected the output gear set. Everything looked good then, and I was in a rush to put the transmission back together. I recall the 5th gear C-clip in place, but opted not to disassemble the output shaft assembly since all the gears spin freely, the teeth looked in perfect shape, the synchronizers were in good shape, and the bearings were in good shape. The only thing that I couldn’t see is the dowel pin to the 5th gear bushing and the keys to the splined collar that the 2/3 synchronizer rides on. I don’t expect that the dowel pin could have caused the popping noise and surge in the driveline.

Oddly enough, the 2/3 synchronizer has no damage whatsoever. I even inspected using a 5x eye loupe. My guess the inability to shift to 3rd had something to do with the 5th gear being able to travel forward on the shaft. I’m pretty sure the squeaking in 3rd on deceleration was due to the 5th gear riding on the synchronizer. It can’t possibly be the 3rd gear bearing since 3rd is locked with the shaft when in gear. This forces 1st, 2nd, and 5th to spin at different rates with respect to the shaft. Since 5th was already rubbing, this is most likely the source of the squeak.

I have the 4/5 synchronizer on order and won’t be able to further troubleshoot until I get this back together.

 

[rickf]

I think you have probably found your problem. I also think you said the key words, " I was in a rush to put the transmission back together". That is when things go bad usually.

 

[Jeepsinker]

Yes, if you had any gears trying to engage when they shouldn't, or teeth that should be engaging not fully engaging then that certainly would have caused all of that.

 

[porkysplace]

Time to pull the transmission and completely disassemble and verify the condition of the parts . There has to be ton of metal shavings through out the transmission wether steel or brass causing other damage.

 

[chigger]

Can I get a count of how many times you guys have rebuilt a Spicer 3035 transmission?

 

[swbradley1]

0

 

[Jeepsinker]

1

 

[Wildchild467]

Can I get a count of how many times you guys have rebuilt a Spicer 3035 transmission?

You mean Spicer 3053A?

I took mine part of the way apart to put new synchronizers in it. It wasn't too bad to do with my dad helping me.

 

[rickf]

0, That is why I have not offered any advice at all in that department.

 

[rustystud]

About 20 to 25 times. I used to be a gear man for a company that rebuilt differentials and transmissions. There specialty was Military equipment. They even had 2 running WWII tank retrievers. I almost bought the one, but the owner sold the rear winch off it so I said no.
For those in the Northwest you should remember "Ben's Truck Parts" . All those crates full of NOS WWII parts !

 

[73m819]

This MAY sound DUMB, but DRY spring shackle pins WILL cause this same sound, the springs just about do not work with no load, with a load they are working constantly. Being the OP has tried and tested about everything he can think of, try going outside the box.

 

[chigger]

For the record, my truck has no springs, shackles or dogbones. I have a 4 link rear and a 3 link front with airbags. 18" vertical travel on the suspension. Shocks are custom built 19.5" stroke and set on an angle to gain additional travel. Each wheel can travel over 2 feet in articulation. Before anyone starts into pointing fingers at the suspension, let me say this: The suspension went through several weeks of design to get the calculations to have a bind free link system throughout the entire suspension travel and articulation. Most people skip this part when building a suspension. My links are about 3-4 times the size used in competition monster trucks, and I am not jumping my truck. I've driven the truck as a daily driver for 2 years with no issues before the popping sound started. In addition, I've already inspected all the joints.

 

[doghead]

We could have eliminated a bunch of guessing if you had posted that 56 posts ago.

 

[chigger]

We could have eliminated a bunch of guessing if you had posted that 56 posts ago.

Really???? You going to go there? No one has provided any rational explanation to what is going on. I guess you too are going to point the finger at the something without ever giving a logical explanation of how it can make the driveline jerk under load.

How about this? How many times have you built a 4 link suspension or even calculated out the geometry of a 4 link through the entire travel and articulation?

 

[Rmtaunton]

Easy there chigger... People have been trying to help and offering suggestions for days trying to help you! And yes that was definately huge info you left out ! As now you have huge driveline angles custom brackets and bushings all which can pop.