Noisy Five Speed

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Ich bin ein E9er

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I have had my 70 coupe for just over a year now and am enjoying it immensely. The problem has been a very annoying whine from the gearbox (I thought). The whine pitch gets higher as speed increases. My car some time in its life received a 3.0 engine with Webber carbs and a 265 Getrag five speed. I found a replacement 265 on craigs list and it has been sitting in the garage waiting for me to install it. This past weekend I took the plunge and pulled out the old trans and installed the new one (note that the “new” one is an unrestored used box). So last night after I get everything buttoned up I take her out for a spin. Guess what, same whine. So either the replacement trans has the exact problem as the old one or the whine is not coming from the gear box. Now I need advice from the experts. Is the 265 Getrag prone to whines or should I be looking elsewhere for the cause. I reused the same center carrier bearing and guibo, both seemed fine with no slop in the center bearing and the guibo rubber looked good with no cracks. One thing with the guibo was that the holes didn’t line up perfectly with the holes in the flanges in the trans or the driveshaft. I had to squeeze the guibo with a c-clamp to get the bolts to line up, is this normal? Any input is appreciated.
Thanks,
Steve
 
If noise is there whether clutch is in or out, then problem would be downstream of the transmission. Any bearing can seemingly look ok, but very minor blemishes, flaws or damage can cause significant noise. So you can't rule out the support bearing. Guibo can often be difficult to align with some hammer taps and rotating necessary.

You think the diff might be suspect?
 
Ed,

The noise is only when power is being applied. If I am coasting (off the gas) or the clutch in the whine is not present. And as I stated earlier it is speed dependent, when I shift to a higher gear the whine pitch does not drop with the rpm’s. I guess for the price of a bearing I can eliminate that possibility. As far as the differential, the sound doesn’t seem to be that far back. But I can’t rule it out.

Steve
 
1) the noise you're describing is unlikely wheel bearings (in the rear) unless it is constant and related to rolling speed (and not affected by trans shifts)

1a) noisy final drive you'll notice a change in the whiney-sound under load (when accelerating -vs- coasting or maintaining speed) sounds like this is your prob)

2) the guibo when installed new has a ring clamp around its diameter that is removed after torquing the installation bolts. The rubber in your guibo WILL fail if the bolts are torqued without the rubber restraint. Twisting, squeezing, pushing, prying to "get it in there" will compromise the old rubber, and these can fail in a way that ruins the tailshaft of your tranny, and the added vibration while its getting ready to fall apart will wear out your driveshaft.

2a) center bearing must be preloaded and the driveshaft aligned properly or the resulting imbalances will wear everything out,
 
Dp, thanks for the info.

From your description it sounds like the diff plus a new guibo. What is the process for preloading the center bearing and aligning the driveshaft? Is this something that can be tackled by you average owner/mechanic?

What is the going price for a decent differential?

What cars use the same differential as ’71 2800 CS?

Thanks,
Steve
 
diff

If you need a diff I have a rebuilt 3.45 but its not a limited slip, it has all new bearings and seals and is set up properly. It has 0 miles since rebuild and can be shipped by UPS in a plastic tote with bubble wrap. If you want contact me @ 208-347-3309 and we can discuss details. Leroy
 
Ich bin ein E9er said:
Dp, thanks for the info. From your description it sounds like the diff plus a new guibo. What is the process for preloading the center bearing and aligning the driveshaft? Is this something that can be tackled by you average owner/mechanic? What is the going price for a decent differential? What cars use the same differential as ’71 2800 CS?
Thanks, Steve
Click to expand...

Hi Steve, call Carl Nelson in La Jolla at CNPR / LaJolla Independent, he can supply the guibo and other bits you need for the job. Ask him about RedLine oil as a possible try (with something like Lubro-moly added) as a possible stop-gap to try in your diff before replacing it. I'd also recommend replacing that center support bearing. The preload install isn't too difficult, let it hang slightly, free-state, use a scribe or basking tape to mark where the back edge of the mounting tabs are in relation to the frame rails, then preload by pushing forward both tabs precisely evenly about .080-.100" forward and tightening the nuts to finish torque....remembering that the bearing must remain perpendicular to the driveshaft center line. Carl can confirm/correct the amout of preload to use, he's very helpful and a wonderful asset to all us coupistas. Tell him Phelpsie sent you!
 
waitaminnit

Before you drop substantial bucks as a result of an internet diagnostic effort, you should be certain that the diff, as seems to be suggested, is actually the problem.

I note that a used 5-speed which has been sitting (for reasons not know or stated) may have a problem with the layshaft bearings. These live at the bottom of the trans case, so if there's any water (condensation, whatever) in there, it attacks the layshaft bearings. They will whine for a time but over several hundred miles the whine may almost entirely disappear. Change your trans oil, okay? And drive it a while to assess whether 1. you can live with it, and 2. if it seems to go away.

However there is also the opportunity (imperative) that you perform a proper diagnostic. For me, and I take some risks occasionally, I'd jack up and securely block the rear of the car off the ground. Then have your trusted assistant run it up through the gears while you listen to what's going on. Use a stethoscope or kludge one up, so you can listen to the trans, then the differential. And be sure your blocks are good.

Center bearing preload seems useless to me - what kind of force on the bearing will you exert by moving the thing forward 0.1 inch, when the rubber diaphragm in which the bearing is mounted has taken a semi-permanent sag which is much more than that? But the books all say to preload. Can't hurt, eh?

Nasty things can happen to both good and bad people - but approach the situation with proper care and attentiveness. You may discover that significant cost parts replacement is not in you immediate future, on this matter.
 
Re: waitaminnit

Honolulu said:
Before you drop substantial bucks as a result of an internet diagnostic effort, you should be certain that the diff, as seems to be suggested, is actually the problem.
Click to expand...

I concurr. Not to scold you Steve, but sometimes it pays to take a car in to a pro, and have them diagnose the exact source of the problem. It is usually faster and cheaper to have a shop determine that all you need is a $5 bearing (plus $100 for their labor to install it) than to buy another used tranmission (or whatever), install it yourself, and then find that the tranny wasn't the problem after all. Of course, some "pros" just use trial and error too!

One thing with the guibo was that the holes didn’t line up perfectly with the holes in the flanges in the trans or the driveshaft. I had to squeeze the guibo with a c-clamp to get the bolts to line up, is this normal?
Click to expand...

I have replaced a lot of Giubos on Alfas - pretty much the same design as on Coupes - and the lore there is to use two large hose clamps, connected in series, tightened around the Giubo to compress it. For some reason, those Giubos are made a bit oversize, and need to be squeezed down to get the bolts to line up. When you buy them new, there is often a sheetmetal strap around them to hold them compressed until you get them on - then the strap should be taken off.
 
Re: waitaminnit

Honolulu said:
I note that a used 5-speed which has been sitting (for reasons not know or stated) may have a problem with the layshaft bearings.
Click to expand...

I can't remember if 4th gear is a direct 1:1 ratio in the 265, but if it is, a lay shaft bearing problem is easy to diagnose. Since 4th gear is typically 1:1 in 5spd transmissions it bypasses the lay shaft since it doesn't need to change the ratio, meaning, if you have a whine due to a bad bearing on the lay shaft it will whine in 1st, 2nd, 3rd and 5th. In 4th gear it won't whine.

I'm leaning toward the rear end myself. Does anyone have an extra one in your area that can be used to diagnose?

Dan
 
I did call Carl Nelson earlier this week. I did not have a chance to speak with Carl but did talk with one of his mechanics. After describing the symptoms he felt it was probably the diff or real wheel bearings. We also discussed the installation of the guibo and center bearing and he basically echoed your advice. He also assured me that they have all the parts that I might need to make repairs.

I knew the used trans was a gamble but from what I have heard and read the 265 seems to be a fairly bullet proof unit. And since I already had the gear box sitting around all I was risking was wasting my time. Which in hind sight seems to be the case (although I now believe I have a known good trans sitting in my garage). The thought has occurred to me that maybe I replaced a faulty trans with another faulty trans but I don’t think that is the case. Even if both gear boxes suffered from the same defect it is hard for me to believe that both units would exhibit the exact same pitch of whine. And yes it does whine through all five gears.

It probably would have been smarter to take the car into an expert and have them try and diagnose the problem, but there is a certain amount of scarification in tackling a problem yourself. Even though I replaced a trans that probably did not need replacing I know a lot more about my car now than I did last week. And now I am thinking about doing the same thing with the diff.

This brings me to a new point of discussion, the differential. I drained and replaced the oil today and noticed that there were the remnants of a white painted “S” on the back of the diff case. From what I have learned from searches on this site this designates a limited slip differential. With both wheels off the ground I rotated one wheel and the other wheel turned in the opposite direction. I always thought that this was indicative of an open differential, I then took the car down to a nearby dirt lot and from a standing start popped the clutch and it was quite clear that both tires were spinning. If my car does indeed have an LSD would it be in my best interest to have it repaired? Any idea what it cost to have one rebuilt?

Thanks for all of the replies.
Steve
 
You appear to have a conventional, open differential. You should be able to isolate the whining to the differential, center bearing, or trans by having a passenger with good ears ride in the rear seat.
 
I have spent a little time concentrating on the diff performance; it certainly acts like an lsd. As I mentioned before it spun both wheels in loose dirt, it also did the same thing on dry pavement. I also tried it with one wheel in the dirt and the other on pavement, when I took off the tire on the pavement gave a chirp with no spinning on the dirt side. It certainly behaves like a posi.

Steve
 
"S" on diff

The painted "S" is supposed to indicate LSD, but over time, wear may destroy the effectiveness of the internals clutches. Originally the diff was 25%, not a lot, but it's a street version for sale to any and all. Higher percentages induce more tire wear...

Since no one here has chimed in, Carl or one of his people could probably suggest who might be able to repair/rebuild the diff, including changing the slip ratio. It's just a matter of shimming it correctly.

I see Mario Langsten on another post - he too could likely make a suggestion as to a fixer.
 
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