Vibration in 3rd and 4th

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appetite
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Vibration in 3rd and 4th

Post by appetite » Sat Jun 20, 2020 6:28 am

Hi all,

Don't know if anyone is still around these parts, but...

69 Bus with a 1600DP, tranny rebuilt less than 5000 miles.

I have a vibration and a rattling that comes through the shifter that occurs only in 3rd and 4th and only on acceleration. The sound goes away on deceleration and in the lower gears.

I will check the bushing up front, but is there anything else i should trace back to the tranny?

Thanks,

James

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Re: Vibration in 3rd and 4th

Post by appetite » Sun Jun 21, 2020 2:58 pm

So I think i found the culprit.

As per Robbie's suggestion, i adjusted the valves this morning. They were all tight.

After the adjustment, I took her out for a test drive. The rattle was still apparent, but the vibration had diminished considerably.

So I'm pleased and mortified. Pleased that this might have been the cause of the vibration, but mortified at the possibility that the valves were so tight as to cause that level of movement through the engine and up and down the drivetrain.

As i said, the rattle is still there, but that I chalk up to the bus being 50 years old, likely with the original bushings.

James

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Amskeptic
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Re: Vibration in 3rd and 4th

Post by Amskeptic » Sun Jul 05, 2020 10:32 am

... update for the readership. Transaxle packed it in. We are waiting for the failure report.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

appetite
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Re: Vibration in 3rd and 4th

Post by appetite » Sun Jul 05, 2020 12:12 pm

Remember when I said I thought adjusting the valves took some of the vibration away, but the rattle remained? Well today, total, utter breakdown!

I was pulling away from a dead stop, shifting from 1st to 2nd and I heard a "bang" from the rear, almost as if it had jumped out of gear, and the bus lurched and vibrated violently. The loudest and most horrible noises came from the back, as if the engine was seizing (it wasn’t: it is running cool and smooth in neutral at idle). The bus felt like it was coming apart. Oh my!

It is the worst case scenario. Here’s the pieces of the transmission that tumbled out when I drained the gear oil. Time to call the vendor that rebuilt this transmission and see if he will honor the warranty.
teeth.jpg
teeth.jpg (1.34 MiB) Viewed 7578 times

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Amskeptic
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Re: Vibration in 3rd and 4th

Post by Amskeptic » Mon Jul 06, 2020 10:25 am

appetite wrote:
Sun Jul 05, 2020 12:12 pm

It is the worst case scenario. Here’s the pieces of the transmission that tumbled out when I drained the gear oil. Time to call the vendor that rebuilt this transmission and see if he will honor the warranty.
teeth.jpg

Are those actual gear teeth? With a slight curve? Ring and pinion!
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

appetite
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Re: Vibration in 3rd and 4th

Post by appetite » Mon Jul 06, 2020 5:16 pm

They look like teeth to me. What would cause this type of catastrophic failure? I drive my bus so gentle!

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Re: Vibration in 3rd and 4th

Post by Amskeptic » Tue Jul 14, 2020 3:49 pm

appetite wrote:
Mon Jul 06, 2020 5:16 pm
They look like teeth to me. What would cause this type of catastrophic failure? I drive my bus so gentle!

appetite! I am going to guess that some reverse gear intermediate shaft circlip sprang off and landed in between the teeth.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

appetite
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Re: Vibration in 3rd and 4th

Post by appetite » Mon Jul 20, 2020 5:04 am

So Wright Gearbox replaced the broken ring and pinion with another used set. That's where the teeth came from. I had to cover shipping both ways, about $400. That does not include the cost of other materials (grease, gear oil, parts, etc) that I need for installation. This unnecessary breakdown and rebuild failure has become expensive and deeply frustrating. But I digress...

Removing the tranny was the easy (!!!) part. Getting it all back together and running is going to be a challenge. I have a bunch of questions that I hope the forum could answer based on their collective experience. In no particular order:

1. Is it easier to install the engine and tranny as a unit?
2. Can I put the starter on the tranny before installation or will it interfere with guiding the tranny back in?
3. I got a new Throw Out Bearing. The new one is "tighter" to spin than the old one. Both are SACHS, German. New one or old one?
4. When I removed the tranny, I also removed the CVs and axles and wrapped them in plastic to protect them from crud. I realize now that I could have left them on the wheel side and simply wired them off the ground. Now that they are off, do I repack both ends with grease before reinstall? If so, do I remove the old grease? What kind of grease should I use? And finally, do I tighten the bolts using a pattern like lug nuts or in a circle? Anything else here to watch out for?
5. I'm keeping the same clutch, pressure plate and flywheel because they all have less than 7500 miles on them. OK?
6. I have StaLube GL-4 gear oil. Fill until the oil drools out of the case?
7. Any order of operations that i should be aware of? Do this before you do that, etc? Anything else I should be mindful of?

I'm wary now of the quality of the rebuild and repair. I thought the previous tranny would outlast me. I'm worried that the tranny is going to blow to smithereens again. Sheesh.

Thanks all.

James

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asiab3
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Re: Vibration in 3rd and 4th

Post by asiab3 » Mon Jul 20, 2020 11:33 pm

1. Depends on your jack situation and your experience. 50/50 for me.
2. Sure, but it makes the assembly a little right-heavy with the generator installed. See #1.
3. I’ve seen them last months and decades. Stand on it and spin around to sense micro-grit in the rollers? (Go new, and save the old for a rainy day. These are some of the best-made reproduction parts out there.)
4. I pack a little of the same grease that was in there, unless coming up on 30k... If not sure, no time like the present to reset the maintenance clock with Valvoline Durablend or Synthetic grease!
5. My clutch and pressure plate have 150,000 and still measure in spec. If you follow Colin’s driving methods, yours can too. :)
6. Yep, on level ground. VW did a flush ‘n fill at 600 miles on a HOT transaxle before resuming the 30k mike maintenance interval DESPITE WHAT BENTLEY SAYS.
7a. I fill my new transaxles with them standing on their bell-housings like a Saturn V rocket ship. I like to think the oil costs more spinny things that way. Then I stand them on the nose cone for a bit to get the bearings too. I’m sure rebuilders use assembly lube, but most of the nose-cone doesn’t see oil right away in a fresh rebuild.
7b. Many good rebuilds shift extremely tight for the first hundred miles or so. Don’t worry at first; worry if it doesn’t get easier.
7c. Don’t get the wet stuff on the hot stuff, and keep the smoke inside the battery. Seriously, you’ve got this. Don’t overthink it, and let us know how the breeze feels in your hair.

Robbie
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

appetite
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Re: Vibration in 3rd and 4th

Post by appetite » Tue Jul 21, 2020 5:17 am

Deeply appreciated Robbie! I'll report back...

appetite
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Re: Vibration in 3rd and 4th

Post by appetite » Mon Jul 27, 2020 4:39 pm

OK, everything is back in. Lining up the mounts was a challenge, and I made lots of mistakes, including watching a CV joint burst into pieces as I was trying to get it on the wheel side. I nearly gave up. But I regrouped and brought the axel to a mechanic to help me re-pack and reassemble. I think I got the clip secured correctly. And no, I don't think I got the balls in their original spots. We'll see how it survives. Colin: if you ever get back on the road, I have a lot of things I'd like you to check, because lord knows this bus needs some expert attention.

I still need to adjust the clutch cable, adjust the accelerator cable and button up loose ends, like wiring the grub screw to the coupler. I replaced the crumbling engine seals and of course they no longer fit correctly.

This rebuilt tranny feels different than the last one; tighter for sure, but also the shifter in 1st gear nearly hits the dash. Not sure if that is going to be an issue. But it is quiet so far. No vibration. And it goes forward and backward. Imagine that.

Cheers,

James

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