Leaking rear axle seals

[Frango100]

Wouldn´t the 3.50 ratio not cause high rpm/noise during highway driving? I wouldn´t go over 60 mph most of the time.

[simplyconnected]

Rear end gears determine your rear wheel torque. The question is, how easily does your engine turn the rear wheels? We use transmission gears to help but the rear end gear has the final say because it raises or lowers the torque of ALL your transmission gears (depending on the ratio you choose).

If most of your driving is under 60-mph, the benefit of more torque around town will give you 'new found' horsepower and it might even save a little gas because you won't need as much gas pedal to do the same job.

Yes, highway speeds will require more rpm but that is offset if the majority of your driving is done around town. Let's do some arbitrary numbers... Suppose your engine and trans produced 200-ft/lbs of torque in high gear. Now, you multiply that by your existing gear ratio (200 x 2.75 = 550 ft/lbs of torque). The same torque (200) married to a 3.55:1 would deliver 710 ft/lbs of torque, a gain of 160 ft/lbs. This is a serious advantage and a very inexpensive way to gain horsepower without changing your engine, especially at every traffic light from a first gear stop.

[Frango100]

I will need to order the ring and pinion next week, so that my collegue can take them with him when he returns from SFO. I already ordered the master bearing kit.
Even with the 2.75 ratio the Bird would accelerate surprisingly rapid, so i´m still tossing if i will go for the 3.00 or the 3.50.
Decisions, decisions.... .
The rear axle is out, so now i have to find someone who can do the welding.

[OX1]

3.00:1 will be OK for easy cruising.

I have 2.75:1 in my F100 with 429 & C6, it will still smoke the tyres and it will do 100mph in 2nd gear hence why I think even with your smaller motor and 3.00:1 gearing it will get the job done.

I agree, no way I would go anything over a 3.10 for a non overdrive vehicle. The added accel on the low
end is not worth the RPM drone/screaming on the highway at today's speeds. I might consider a different stall
converter instead of gears, but not sure what is avail for the trans in question.

As for the cracked housing. If you fear repairing it again will not be adequate, I would look
for a 9" truss that mounts above axle. Cut out areas that truss crosses over for upper
link mounts, and weld truss to either sides of those mounts.

Realistically, it was probably just a bad weld as to why it cracked again.
(unless you have some horrendous roads that you drive at high speed over)

[Frango100]

Today i was just test fitting the side gears and pinions in the carrier housing. With the washer under the side gear, i can install the pinion pin, but the gears will not rotate at all, even when applying quite some force. This doesn´t seem right. When i remove the washer under the side gear, it rotates all fine. Seems that the washer is a bit too thick. Did this happen to someone on here before? I didn´t try the old washer yet, but will do so just for a test. The washer is there to act as a bearing surface, so should not be left out.

[Frango100]

My colleague just came back from SFO and brought the DANA drive pinion and ring gear set and the repair sleeves from SKF for the axles with him. I went with the 3.00 ratio, just close to the factory original of 3.10.
Now I have to wait for the rest of the parts to arrive via USPS, than I can start the rebuild. Still waiting on an answer from Rockauto regarding the differential side gears and pinions. The kit from USA standard gear doesn´t fit well. At least, the gears do fit well, but when the washers are installed as well, the gears are impossible to move by hand. Seems that they used too close of tolerances on this.

[Frango100]

Just a short update: the rest of the parts came in and the build-up of the differential can start. I already pressed the new bearings on the axles and also the bearings on the drive pinion. I was quite surprised that it needed around 6 T of pressure to get the first bearing on the drive pinion. The pinion nut is already on torque, I will only have to remove it again to be able to install the oil seal. The problem with the too close clearance of the differential side gears is not solved yet. But I did read now that USA Standard gear is a second line from YUKON gears. Yukon gears sells the gears which don´t pass their quality control for the tollerances as USA Standard gear stuff. This seems to be my problem now

[pbf777]

YUKON........... "Off-Shore" manufacturing!!!!

Scott.

[simplyconnected]

YUKON........... "Off-Shore" manufacturing!!!!

Scott.

I feel the same, Scott. But anymore, all of our choices are gone! As long as Americans keep buying Chinese goods, these companies aren't stupid, they will continue to produce the stuff we buy.

[scumdog]

I feel the blame is not so much with the Chinese manufacturer, more with the profit oriented importer who fails to have a good quality control process in place.
I bet the US manufacturers have one.

[pbf777]

As long as Americans keep buying Chinese goods, these companies aren't stupid, they will continue to produce the stuff we buy.

Absolutely correct!!!

I know we're off topic here, but this needs emphasizing until it is understood by the ignorant!

Scott.

[Frango100]

When i had to buy a waterpump for my Jeep, i could get one made in China directly here in Brazil, but i bought one via Rockauto from an "American" brand. I was quite surprised that when it arrived, it stated " made in China" on the box.

[Frango100]

Ok, back on topic: the differential third member is complete and put back in the housing. The differential is loosly installed under the bird and just will need a bit more time to be finished. Will be traveling to Holland tomorrow, so expect to be able to test it after my return, in about a week.

[Frango100]

So today had some time to finish the differential installation and test drive the bird. No more noises from the differential and a very comfortable rear suspension.
With the weight on the wheels, the rear suspension clappers are much more closed than they where before (the vertical clapper bolts and rubbers are not installed). It all drives very well, i only hear some noise from both clapper ends touching each other when the bird comes down after a traffic bump. So at least some rubber should be between the clapper ends to prevent this noise.

[simplyconnected]

...i only hear some noise from both clapper ends touching each other when the bird comes down after a traffic bump. So at least some rubber should be between the clapper ends to prevent this noise.

With all due respect, if I had a '58 T-bird, I would get a torch and cut those clappers off completely. All they accomplish is to restrict freedom of motion which is what you don't want. Furthermore, they transfer torque to the upper control arms! Again, something you don't want.

So for now, you have your proof. This explains why no other trailing arm suspension uses 'clappers', across all car lines and models. - Dave