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Driveline vibration in 1979 Ford L800 429 gas 5+3 brownie
Well, I see it's been a while since anyone posted in this thread so it's time to wake it up.
First a little history. I bought this truck to help our son-in-law w/ planting and harvest. It's a former fleet truck. Previous owner drove and worked on the truck since new, then bought it from the company 12 years ago. It's been his pet project ever since. He came onto some hard times and had to sell.
Just before the company sold it, the engine was rebuilt, 5 speed and rear end got new bearings and the two-piece rear driveshaft w/ carrier was removed and replaced by a one-piece shaft. It starts, steers, stops and runs just fine. Previous owner was a good guy and very meticulous. Put different cab on it and fixed all the little things that needed fixing.
Now for the vibration. The last thing that needs attention is the driveline vibration. It starts at about 35 mph, gets very noticeable between 45-55 mph. At 56 mph it smooths out and almost completely disappears.
I've read this entire thread a couple of times and learned a bunch about brownies.
The brownie in this truck is a factory installation.
I'm guessing the vibration is either in the front driveshaft or the big brake drum hanging on the back of the brownie. And all the rubber bushings are old and hard and need to be replaced. But I realize it could be other things too, so I'd be glad to hear your thoughts on what might be causing it and how to go about fixing it.
I've put a picture of the truck and the brownie set up in my photo album.
I know that one solution is to remove the brownie and put in a two-speed rear end. But I really like that old brownie and I'm hoping to keep it in there.
In my old Dodge Power wagon (c pic) it has a 5831A Brownie and the lower shaft is out of balance. Once we took out the top shaft the lower shaft rotated on its own till the heavy end was down. This is were I believe I'm getting my vibration from.
To bad I didn't take a picture of the lower shaft were it looks like the front part of the shaft screws onto the rear section. The reason for thinking this way, both bottom shafts have a raised boss and they were not lined up perfectly. The raised bosses were about 1/8 from being lined up. These two raised bosses seem to course the lower shaft to be off balance.
Am I correct to assume there is a front and rear section of the bottom shaft?
Can I drill out these raised areas to try and balance the lower shaft?
Many possibilities??? Perhaps easiest item to confirm as good or bad is the drive line. Take drive shaft to shop then can spin it to check balance and out of round. This is a common issue when a driveline is shortened the shorter the shaft the more perfect the yoke alignment and weld need to be. There is also phasing of yokes. I have this same issue in my one ton and I know it is because the shaft was cut on a chop saw and welded in place by eye. Sometimes I get in a hurry and short cuts are not always so short.
Thanks for the replies. I'm a novice when it comes to driveline issues so I've been doing a lot of searching and and found some good info. For example, here's a link to a site I found helpful:
Thank you for the reply George. We made it home with the Power Wagon and I've pulled the Spicer 5531A auxilary transmission out. This transmissions lower shaft is out of balance (looks like 2 shafts, c pic) so I'm trying to pull it apart but no luck. Unfortunately it's a little different than the 5831 diagram you posted above.
I can't pull the top rear main shaft out because the end does not have a C clip like the 5831 model. Can you please advise me on how to get it apart? Would you happen to have any info on this 5531 unit?
picture shows normal separation between input and main shaft. If rear bearing is removed the shaft will tilt up and out. Shaft cannot be removed until the bearing comes out.
Thanks you Sir! Just tried it and the top shaft came right out.
Any tips for removing the lower shaft?
I'm tearing into this Brownie because I'm tired of the vibration coming from the lower shaft. With the top shaft out I can rotate the lower shaft up by hand and gravity will rotate it back down. Been working on this truck for 9 years and this vibration drives me nuts
The picture above of is taken through the pto opening. It looks like it's a two piece shaft with raised bosses on it. Any idea why this lower shaft would be so off balance?
remove bearing cap from rear counter shaft. Use a hardwood dowel or other suitable tool (large brass drift) to drive counter shaft as far back into the case as it will go to remove the rear roller bearing then the counter shaft comes out the same as the upper shaft did. A double gear is keyed and pressed onto the counter shaft. Several possibilities for noise. First nearly all are noisy. The double gear may be out of balance. Woodruff key may be sheered off. Out of balance gear or shaft may have caused elliptical wear on the shafts roller surfaces. Any competent machine shop can spin the shaft with and without the removable gear and locate the source of the issue. Since it has been that way many years it is amazing it still has bearings. In any case a good machine shop can repair or balance the shaft and or gear.
G, as I was removing the top shaft these two little keeps fell down into the case. I could only find two. looks like they would ride between a gear and the shaft. Any ideas?
This thrust washer rides on the top shaft and one little tab is broken were it rides in the grooves on the shaft. Should I be looking for a replacement washer or you think it's ok?
G, I talked to a few machine shops and drive line too and they all say they have no way to balance it. A drive line they can tach weld a weight on but not the hardened gears and guarantee it will stay.
You got any tips or suggestions to getting it balanced?
You need a real machine shop. All they have to do is chuck it in a lathe and check the surfaces with a dial indicator to determine where the thickened out of round parts are.
This is simple machine shop basics. To balance without a lot of machine work can be done the same as a manual transmission flywheel. They drill divots in the thick outer rim.
Any machine shop that cannot balance a rotating mass is not a place to have work done.
To turn out of round hardened parts is very expensive. Its labor intensive and very hard on tooling that only makes periodic contact with a thickened surface.
10-07-2014, 09:24 AM
