Driveline Questions

It all seams reasonable. Yes, the engine mounts are not fun when you have to lay in the driveway to do it. Never heard of that brand of parts, but I dont live near AZ either. They are probably good if they get them from a major parts supply. The cause of your problem is most likely the center support, but it sure wouldnt hurt to do the u-joints while the shaft is out. I dont recall ever having had to balance a driveshaft exept if it was damaged or the length changed for some reason. They probably want to balance it to make sure it is ok and to make a few more bucks at the same time....(you cant loose on that one)

>

One more thing...They said the motor mounts are "fair", I'd leave them alone for now and save $220

snip

I'd recommend the rear tranny mount first. Very easy to replace, must be a factory part, not a jobber. B

~

Driveline Questions Group: alt.trucks.chevy Date: Mon, Oct 6, 2003, 4:52pm (CDT-2) From: snipped-for-privacy@nospamcox.net (Robert=A0L.=A0Wells) =A0 =A0=A0=A0=A0=A0=A0=A0I have some rumbling and vibration in my 1977 C10

2WD 454 Chevy Suburban that occurs between 25 and 35 MPH. It also clunks going to drive or reverse.

Front end is solid and freshly aligned and the tires have been balanced.

The vibration seems to be more pronounced under acceleration and going around a left curve.

I took it to a driveshaft shop here in the Phoenix AZ area and he told me the motor mounts were in fair condition, tranny mount is bad and needs replacement and he will have to remove the driveshaft to check it out.

There prices (tax included) are as follows; =A0=A0$100 - tranny mount $220 - engine mounts $68 - driveshaft removal/inspection/reinstall

=A0=A0=A0=A0=A0=A0=A0=A0I also asked about drive shaft overhaul figuring that everything is original equipment meaning 26 years old and about

145k miles and hauled a 24ft travel trailer for first 50k miles and has since been driven by myself (moderate leadfoot). The quote was: $293 - new universals w/fittings(3) + new center support bearing (all Neapco parts) and balancing

=A0=A0=A0=A0=A0=A0=A0=A0My questions are:

Are these decent prices?

Are Neapco joints and bearing good quality?

What's involved in changing the tranny mount?

Am I correct in assuming that the engine mounts would be a bear?

Two of the U-joints are held in with the funny looking clips and the diff yoke has injected clip. Tech said shafts with injected clips need to be rebalanced because bearing position may change when replaced. Is this true?

=A0=A0=A0=A0=A0=A0=A0=A0I would like to do the driveshaft myself (making sure i keep everything lined up properly) and replace the tranny mount. Any suggestions?

Thanks, Bob ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Bob, The only bothersome part of the symptom, is the "pronounced going around curves" part.

If you are sure the front-end is up to par, I would suggest having the rear axles looked at for bearing wear and "plunging" , before you go to the expense of the other repairs.

You should be able to handle the u-joints and tranny mount with little or no difficulty. But the symptom is more likely associated with an axle. "pronounced on turns".

The prices seem just a bit high to me. But then again I'm use to doing Chev tranny mounts for around $50-$75.... motor mounts for $75 plus parts.....NO CHARGE on R&R driveshafts to diagnose u-joints. But then again, I don't usually get stiffed on loosing the repair, because my diagnosis is pinpoint 99% of the time.

~~Great Customer Service....brings forth.... Great Customers~~

SUGGESTIONS.....4-U......

At a minimum, get a 2nd opinion on the rumbling and vibration. Have the axles checked too.

Tackle the driveshaft yourself. Your going to save at least $75 or more on that alone, even if you CARRY IT TO A MACHINE shop to get the actual parts replaced, once you have it out of the vehical. (hint...hint)

Tackle the tranny mount, use a NAPA mount if at all possible. Again, about a $35-$50 savings minimum. The mount shouldn't cost more than 25-35 bucks.

GO TO A TRANNY SHOP AND GET A DIAGNOSIS AND ESTIMATE............... they deal with u-joints, eng.mounts, tranny mounts, and vibrations everyday. You will be very suprised at the difference in the estimate when you utilize an establishment that deals with the affected repair on a daily basis.

hopefully informative,

Scrib Abell (tranny dude) ~:~ would give up his day job ......just to yank driveshafts all day long at those prices ~:~

~ (read the thread if yuh like.....or not...)

Robert, an addendum if I may........

when I do a set of u-joints, or a "center support" bearing, I yank the driveshaft and send it out to the machine shop at the parts house I buy my u-joints from.

They don't charge me labor on the parts installation, as long as I purchase their parts.

just a thought...... it never hurts to ask your parts guy! The worst that could happen....he'll say no.

any whoooo.... good luck and let us know

Scrib Abell

Thanks for your inputs Scott. Since you talk about doing engine mounts in the driveway, I have a question for you. I have looked far and wide for a source of good wheel chocks in the Phoenix area. I can't believe that nowhere (including AutoZone, Checker Auto or Napa) have I found wheel chocks. I found some at a RV place but they are the hard plastic type that would be useless on my smooth garage floor. I saw some online at

that look real good but the shipping would be pretty stiff. Any idea on what other kind of places to look?

Thanks, Bob

Thanks for your inputs Scott. Since you talk about doing engine mounts in

Bob,

Try anywhere that sells safety equipment like Grainger.

Kyle

Driveline Questions

Group: alt.trucks.chevy Date: Mon, Oct 6, 2003, 4:52pm (CDT-2) From: snipped-for-privacy@nospamcox.net (Robert L. Wells)

I have some rumbling and vibration in my 1977 C10

2WD 454 Chevy Suburban that occurs between 25 and 35 MPH. It also clunks going to drive or reverse.

Front end is solid and freshly aligned and the tires have been balanced.

The vibration seems to be more pronounced under acceleration and going around a left curve.

I took it to a driveshaft shop here in the Phoenix AZ area and he told me the motor mounts were in fair condition, tranny mount is bad and needs replacement and he will have to remove the driveshaft to check it out.

There prices (tax included) are as follows; $100 - tranny mount $220 - engine mounts $68 - driveshaft removal/inspection/reinstall

I also asked about drive shaft overhaul figuring that everything is original equipment meaning 26 years old and about

145k miles and hauled a 24ft travel trailer for first 50k miles and has since been driven by myself (moderate leadfoot). The quote was: $293 - new universals w/fittings(3) + new center support bearing (all Neapco parts) and balancing

My questions are:

Are these decent prices?

Are Neapco joints and bearing good quality?

What's involved in changing the tranny mount?

Am I correct in assuming that the engine mounts would be a bear?

Two of the U-joints are held in with the funny looking clips and the diff yoke has injected clip. Tech said shafts with injected clips need to be rebalanced because bearing position may change when replaced. Is this true?

I would like to do the driveshaft myself (making sure i keep everything lined up properly) and replace the tranny mount. Any suggestions?

Thanks, Bob ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Bob, The only bothersome part of the symptom, is the "pronounced going around curves" part.

If you are sure the front-end is up to par, I would suggest having the rear axles looked at for bearing wear and "plunging" , before you go to the expense of the other repairs.

You should be able to handle the u-joints and tranny mount with little or no difficulty. But the symptom is more likely associated with an axle. "pronounced on turns".

The prices seem just a bit high to me. But then again I'm use to doing Chev tranny mounts for around $50-$75.... motor mounts for $75 plus parts.....NO CHARGE on R&R driveshafts to diagnose u-joints. But then again, I don't usually get stiffed on loosing the repair, because my diagnosis is pinpoint 99% of the time.

~~Great Customer Service....brings forth.... Great Customers~~

SUGGESTIONS.....4-U......

At a minimum, get a 2nd opinion on the rumbling and vibration. Have the axles checked too.

Tackle the driveshaft yourself. Your going to save at least $75 or more on that alone, even if you CARRY IT TO A MACHINE shop to get the actual parts replaced, once you have it out of the vehical. (hint...hint)

Tackle the tranny mount, use a NAPA mount if at all possible. Again, about a $35-$50 savings minimum. The mount shouldn't cost more than 25-35 bucks.

GO TO A TRANNY SHOP AND GET A DIAGNOSIS AND ESTIMATE............... they deal with u-joints, eng.mounts, tranny mounts, and vibrations everyday. You will be very suprised at the difference in the estimate when you utilize an establishment that deals with the affected repair on a daily basis.

hopefully informative,

Scrib Abell (tranny dude) ~:~ would give up his day job ......just to yank driveshafts all day long at those prices ~:~

Hello Scrib, Thank you for your help. I assume the only way to properly evaluate the rear axle bearings would be to pull them out. Something a novice like I could tackle? If not is a tranny shop or the driveshaft shop the better bet and what might be a fair price? Do they also need to check the inboard /diff axle bearings?

I recently changed my diff fluid and I think only about 1 quart of fluid came out and it did not look too dirty. No visible metal sparkles or shavings and very minimal sludge(not bad for 100k miles since last service. I noticed the two holes at 3 and 9 o'clock just inside of the case flange. I assume this is where the diff fluid gets slung into the axle tubes so the rear axle bearings stay lubed. I stuck my finger into the large hole and there was 1/4 inch of soft black sludge in the bottom and it had some very fine sparkling bits of what I assume is metal.

Is it possible that so much fluid had leaked out of my diff gasket over time that none made it through the holes and my outboard axle bearings were starved for lube? For the heck of it I squirted some gear oil into one of the holes thinking I might partially fill the axle tube. When I did it just started running back into the diff case somewhere around the inboard bearing. Is that normal drainage? I filled the diff with about 1.75 quarts (till it ran out the fill plug), drove it around a bit and let it sit for 10 minutes and it took maybe another 1/4 quart. Two quarts seems like a small amount since the range for the different differential capacities in my chevy shop manual range from 4.2 pints for a 8.5 inch ring gear to 14 pints for a

12.25 inch ring gear. Unfortunately I don't know what ring gear I've got short of pulling the cover again.. My dad did tell me at one time he got a diff especially for pulling a trailer so I assume that means a larger ring gear and thus larger capacity. Can't remember whether it was something like a 411 or 353 but i know it wasn't the standard.

Thanks , Bob

grainger doesn't do retail, they're wholesalers.... if you own or know someone who owns a business, they'll sell to you.

-Bret

~~ with concerns of "rumbling noise" and vibrations that are pronounced on turns and accellearation......

(Robert L. Wells) writes in.......

Hello Scrib, =A0=A0=A0=A0=A0=A0=A0=A0Thank you for your help. I assume the only way to properly evaluate the rear axle bearings would be to pull them out. Something a novice like I could tackle? If not is a tranny shop or the driveshaft shop the better bet and what might be a fair price? Do they also need to check the inboard /diff axle bearings? =A0=A0=A0=A0=A0=A0=A0=A0I recently changed my diff fluid and I think only about 1 quart of fluid came out and it did not look too dirty. No visible metal sparkles or shavings and very minimal sludge(not bad for

100k miles since last service. I noticed the two holes at 3 and 9 o'clock just inside of the case flange. I assume this is where the diff fluid gets slung into the axle tubes so the rear axle bearings stay lubed. I stuck my finger into the large hole and there was 1/4 inch of soft black sludge in the bottom and it had some very fine sparkling bits of what I assume is metal. =A0=A0=A0=A0=A0=A0=A0=A0Is it possible that so much fluid had leaked out of my diff gasket over time that none made it through the holes and my outboard axle bearings were starved for lube? For the heck of it I squirted some gear oil into one of the holes thinking I might partially fill the axle tube. When I did it just started running back into the diff case somewhere around the inboard bearing. Is that normal drainage? I filled the diff with about 1.75 quarts (till it ran out the fill plug), drove it around a bit and let it sit for 10 minutes and it took maybe another 1/4 quart. Two quarts seems like a small amount since the range for the different differential capacities in my chevy shop manual range from 4.2 pints for a 8.5 inch ring gear to 14 pints for a 12.25 inch ring gear. Unfortunately I don't know what ring gear I've got short of pulling the cover again.. My dad did tell me at one time he got a diff especially for pulling a trailer so I assume that means a larger ring gear and thus larger capacity. Can't remember whether it was something like a 411 or 353 but i know it wasn't the standard.

Thanks , Bob ~~~~~~~~~~~~~ ~~~~~~~~~~~~~ Bob, first things first.........

I have rebuilt only a couple dozen rear-ends over the last 27 years. This qualifies me to be a "Mechanic"......unfortunately what you need is a "Technician"!

_ _

0 0 L O

However............... I got enough of a clue to give you some pertenant info, without misleading you.

so.....with that in mind.....

My greatest concern would be throwing money at a symptom not knowing EXACTLY what was causing the symptom. Something that I have always frowned on , and consider a definate sign of mediocre diagnostics. Like I stated before, the noise showing up on turns......would lead ME to check for something that is being affected by the turning force. Experience in diagnosing vibrations and "rumbling" noises would take me to a Tire or Bearing first, when combined with the event of the symptom.

You should very easily be able to check the axle bearings, if that is what's causing the noise. If they are worn enough to cause a vibration and a rumble sound, just lift the rear off the ground........using a stethescope..... spin the tires by hand SLOWWWWLLLYYY... and listen for a bearing growl on the axle housing......just where the "backing plate" for the brakes , meet the axle. On a bad bearing it will have a definate "tumbleing, rumble" to it. If the sound isn't smooth....but instead sounds rough, course, or gives the simblance of a washboard effect....the bearing is bad. If the bearing is bad enough to cause the noise you've described, you may likely here it by running the truck in low gear with the wheels off the ground. But try spinning them by hand first. Don't wanna see you get the stethescope hung in a spinning wheel and yank a ear off.......

As far as the lube situation..... If you found sludge in the housing with signs of metal flakes, I would suggest investegating that further. Even if the axle isn't the culprit of your symptom......set some time aside in the near future to drop the cover again and take a closer look. "Some" metal is not a bad thing......but sludge and lots of flakes can be.

Your primary concern should be to narrow down the vibration and rumble, before you go throwing money at it. I would suspect that the u-joints are very likely bad, but the condition of the symptom.....indicates to me that you should be sure that you check axle bearings. For no other reason than to "Nail" the problem completely on the first repair.

Now.........a monkey wrench.......

be sure you check all your tires ...... make sure you don't have a tire, or tires, that are bad enough to cause a vibration and rumble....be sure you don't have a "chopped" tire causing the noise.

Rule out ALL tangents....before you spend your hard earned money on a repair that's needed....but doesn't fix your symptom. There's nothing worse for a technician to do... than make a legitimate repair....only to find out it didn't cure the symptom. It can be hard at times to get the customer to believe that those u-joints were actually bad.....if his symptom is still there.

Any whooo.........

check it out and let us know... and if you find that the axle bearing are the culprit, and need a "Technician" to walk you through the repair......

I will defer to greater minds........which "are" lurking about in here.

good luck.......now get to it ....the clocks ticking and the customer wants his truck back. respectfully, Scrib Abell

Grainger has a store here. You can walk in and buy anything from their catalog.

Kyle

do you have a tax # or are buying it through an account? the local grainger store here is wholesale only and they require your tax ID #.

-Bret

so tell them you are a sole proprietorship and they'll use your Social Security number for an ID number...........

Bret,

I wasn't aware that you needed to give them any such info. I usually just pay cash and get what I want. The guys there do know me from my work, so they may just put everything through that corporate account.

Cheers, Kyle

I don't have to as I just use my employer's account.... that strategy can bite you in the ass as when a state (i.e. Maine, where I live) gets very aggressive in collecting back taxes (amesty period ends next month, I believe). their biggest push is for unpaid use taxes from wholesalers/out of state/mail order. the state most likely will go through wholesaler's records and compare the tax ID's given to the taxes paid. suddenly the 20 bucks in sales tax you didn't pay becomes a $500 bill from the state bureau of taxation.

-Bret

the state's slogan for the amnesty period is "Get to us before we get to you".... kinda makes you feel all fuzzy inside doesn't it? ;-[