What's that sound

Gecko · Jan 25, 2015

So I've got this whining/whirring sound coming from my truck. Sounds kinda like reeeaaaarrrrrrrrrrrrr. It moves with the spedometer and not the rpms so I'm trying to figure out what the problem is. So far there has been no difference in how the truck drives or anything. But the noise is there. Anyone have any ideas? I'm thinking maybe the rear diff or driveshaft? Maybe (hopefully) just a wheel bearing or something like that too.

I'll be heading to the shop tmw to have them take a look. I'm just trying to get some potential thoughts before I go.

charonblk07 · Jan 26, 2015

Lol, starting to find the weak points already? I'd lean more towards bearing or DS, gears typically have a nice crunching or whirring sound when they start going south.

Redtruck-VA · Jan 26, 2015

Leaking from the pinion seal?

Gecko · Jan 26, 2015

I don't have any leaks as far as I know. I did have a leak in the diff a couple months back but when I had the fluids replaced we changed out the gasket and I haven't had a leak since.

I'll be able to check later today or tomorrow if there actually is a leak since we are getting this blizzard and it will leave a mark in the snow.

We are in a "state of emergency" here so I couldn't get my truck to the shop today. We will see about tomorrow.

And kurtis I'm thinking it's a bearing or a wheel hub. I had a hub go out last year around this time too. Could just be because of the cold and general maintenence. That's what I'm hoping.

ATC1500 · Jan 26, 2015

Just had to replace the front right hub a couple weeks ago. pain in the ass cause it was so corroded. easy enough job. just needed a BIG HAMMER to get it off.

Gecko · Jan 29, 2015

So it's way worse than I thought. Was just told that the rear pinion in the diff is roasted. So now I need to figure out what I'm going to do.

What are my options lol

Redtruck-VA · Jan 29, 2015

I would think it's just the bearings that need to be replaced. If the gear set (R&P) are re-used then it is simply changing bearings and using the same shim setup. Isn't SuperShaft in your area? I would go to him if you can. Plus that is not a bad driveway job with the axle tool, dial indicator and a torque wrench. Take the pinion to a shop to press off/on the bearing.. The new crush collar may be difficult to get right in the driveway. I just remembered I had to go to a shop to get mine right the last round. I'm getting old and couldn't crush it by myself. lol

Gecko · Jan 29, 2015

Redtruck-VA said:
I would think it's just the bearings that need to be replaced. If the gear set (R&P) are re-used then it is simply changing bearings and using the same shim setup. Isn't SuperShaft in your area? I would go to him if you can. Plus that is not a bad driveway job with the axle tool, dial indicator and a torque wrench. Take the pinion to a shop to press off/on the bearing.. The new crush collar may be difficult to get right in the driveway. I just remembered I had to go to a shop to get mine right the last round. I'm getting old and couldn't crush it by myself. lol

I just did a quick look up of SuperShaft and they are fairly close to me. They are even closer to my buddy who I do all my work with. I'll have to get in touch with them.

As for the driveway install I'm sure we could do it. But I'm not sure I want to do it in all this snow we have right now...

Maybe I should just upgrade the whole thing (a DTT or an Auburn)? Maybe some new gears? (This damn site won't let me stop modding my truck! :naughty:

)

I guess I should figure that stuff out...

Redtruck-VA · Jan 29, 2015

If you have any intentions to change either differential or gears, this is the time to do it. Why do the same work twice?

Gecko · Jan 29, 2015

Redtruck-VA said:
If you have any intentions to change either differential or gears, this is the time to do it. Why do the same work twice?

I never really thought about changing the diff before (until now) but with having the SC on there I guess it would be a good idea. And I've been toying with going up to 4.10s from the stock 3.92s. I know, not a huge difference but originally I didn't want to spend the money to machine out the diff, which I guess isn't needed for the DTT. I've also heard that the 4.10s are more streetable than the 4.56s and I don't really go to the track.

Redtruck-VA · Jan 29, 2015

With a SC installed I wouldn't change gear ratio, but would want a stout differential like a DDT or something similar.

Gecko · Jan 29, 2015

Is the DTT a straight swap? Or what is involved with swapping it out?

And not that I don't believe you, (cause I think the 4.10s might be overkill as well) but why do you think the 3.92s would be better than the 4.10s with the SC?

I'll also add that the cam I'm running was recommended because I said I wasn't going to 4.56's. It is meant for use with 3.92s or 4.10s

Redtruck-VA · Jan 29, 2015

Gecko said:
Is the DTT a straight swap? Or what is involved with swapping it out?

And not that I don't believe you, (cause I think the 4.10s might be overkill as well) but why do you think the 3.92s would be better than the 4.10s with the SC?

I'll also add that the cam I'm running was recommended because I said I wasn't going to 4.56's. It is meant for use with 3.92s or 4.10s

All your bits and pieces need to compliment one another. Gears, tire size and cam have to be designed to squeeze what the motor has to offer at the rpm you engineer for such as trap speed. With FI you are doing the same as increasing engine size. A rough calculation would be your boost percentage of 14.7psi is roughly the size your increasing the engine. So consider 8psi boost would give you the equivalent power of a 533 ci engine all at the same trap speed of say 6000 rpm. There are various losses involved due to hp needed to turn the pump and added heat losses, but hopefully you get the idea. Gears give a better mechanical advantage to turn the tires to move the weight, if this advantage is so great as to become too easy then the power is wasted in relation to forward motion. You want to have a balance and keep the engine/gear/tire loaded utilizing it's power efficiently. Stated simply, bigger the power less gear is needed. You may find your 3:92 gear is too much gear. Anyway hopefully the FI guys can explain better...

ST-8 · Jan 29, 2015

If you got 3.92s already just get a dtt an new 3.92s an be done. But if you wanna step it up you might as well do 4.56s, 4.10s isn't much of a noticeable jump. Are you 4wd?

Gecko · Jan 29, 2015

Redtruck-VA said:
All your bits and pieces need to compliment one another. Gears, tire size and cam have to be designed to squeeze what the motor has to offer at the rpm you engineer for such as trap speed. With FI you are doing the same as increasing engine size. A rough calculation would be your boost percentage of 14.7psi is roughly the size your increasing the engine. So consider 8psi boost would give you the equivalent power of a 533 ci engine all at the same trap speed of say 6000 rpm. There are various losses involved due to hp needed to turn the pump and added heat losses, but hopefully you get the idea. Gears give a better mechanical advantage to turn the tires to move the weight, if this advantage is so great as to become too easy then the power is wasted in relation to forward motion. You want to have a balance and keep the engine/gear/tire loaded utilizing it's power efficiently. Stated simply, bigger the power less gear is needed. You may find your 3:92 gear is too much gear. Anyway hopefully the FI guys can explain better...

I understand what your saying. I was just curious.

ST-8,

I thought about 4.56s but I don't want to have to grind out the front diff as I believe that's what has to be done (yes I'm 4x4). Also I think the 4.56s are too high a gear for my cam. Atleast that's what I was told when ordering it. That's why I was considering the 4.10s cause those would be a little better suited to the cam. I'm still not set on the gears but I'm thinking I should do the DTT since I wouldn't have to worry about it again after that.

Also I talked to the guy at SuperShaft and he had me check to make sure my driveshaft wasn't backing out (it's not). He says that that's a good thing and that it may just be bearings going bad that need to be replaced. he really knew his stuff and I'll probably be using them. I just need to decide on what I want to do really.

Redtruck-VA · Jan 29, 2015

IMO, I would change the differential and keep the gear and tune to it...

What's that sound

Gecko

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