Been a while since I posted here. Been busy sorting through little issues with my 1969 Mach 1.
Anyway, one of the items I recently changed was the ring and pinion gears. Had a 3.89:1 ratio Motive Gear Performance series gear set that worked great and quite. Down side was even at 50 MPH the motor RPM was higher than I prefer. So I tried a 3.70:1 ratio. Same type, Motive Gear Performance series. This set has let me down. Setup was easy, good pattern, backlash and bearing preloads great. But, noisy on acceleration from about 10 MPH to about 35 MPH. At least now at 50 MPH the motor RPM is tolerable and runs cooler too. getting a rear axle ratio for 60-65 MPH cruising speeds just won't happen because the close ratio toploader trans has very high first gear, something only like 2.32:1. So I'll settle for a 50 MPH cruise speed.
Finally, my question, has anybody used Yukon ring and pinions? A little more expensive but they have great reviews everywhere I look. I also considered US Gear but they have the same part number as my troublesome Motive Gear Performance series.
What is going on with Ring and Pinion gear companies? Are most of them buying from one manufacturer in either India or Italy. Most seem to have the same base part numbers with a simple prefix change.
I purchased 3.89 Yukon gears for my car and have not experienced any noise issues during acceleration and deceleration with this brand of gears. Just an idea in regards to the motor revving higher RPM's at 50-60 MPH, I changed to a taller tire which reduced the RPM's by approximately 300-400 RPM's. Not as noticeable of a difference as installing a 5 speed transmission but enough to make for a slightly more enjoyable ride on the highway. Anyways, I prefer to take back roads as there is much more to see and do than what the highway has to offer. Although my car has been off the road all winter if I remember correctly I was at about 3,000 RPM at 60 MPH.
Tire size, that's a good point. For the minimal RPM difference from 3.70:1 to 3.89:1, I might put the 3.89:1 gears back in. I made notes of the pinion shims etc. for them plus they were quite.
I agree...at least you know the 3.89 gears will work. Will the supplier take back the other gears or are you stuck with them?
A quick question, if you are reinstalling the old gears do you need to install a new crush sleeve when setting the pinion preload? I have heard it is possible to reuse the original crush sleeve as long as you make two marks, one on pinion nut and one on the carrier, and count the number of turns it takes to remove the nut. When reinstalling the pinion nut to the same number of turns as long you the two marks line back up the preload should be set correctly. Sounds logical to me as long as you do not overshoot the marks.
I had these 3.70:1 gears for about 6 months before I was able to drive the car. So I am far past the return policy. They were from Summit Racing and once in the past I needed to return Valve Covers that would not fit that didn't qualify for return because I modified them. Summit's solution which I gladly accepted was to sell me a different set of valve covers at 30% off the price listed on the Website/Catalog. So It might be worth a phone call for these noisy gears.
As far as reusing a crush sleeve. I have done that many times when replacing a pinion seal on the car. Never had a problem. Like you mentioned, reinstall the pinion nut in the same location as original.
My third member is an old Ford Nodular case with a Daytona pinion housing. It uses a solid spacer instead of a crush sleeve. As I found out, every time a pinion bearing is replaced it seems the spacer thickness needs to be changed. Even when staying with the same brand (Timken) bearings. A thickness change of 0.0005" of a spacer or bearing inner race makes a huge difference. It can be time consuming slowly narrowing in on the correct thickness without overloading the bearings.
I often find myself in similar situations with being past the return policy. Many times I purchase parts for my projects well before my plans to install them. It is more of a cash flow thing. When I have extra cash I squirrel away everything I can. Right now my basement is stockpiled with Fairlane parts waiting to be installed. I can only keep my fingers crossed they will fit/work!
In regards to the solid spacer that makes sense too. Correct me if I am wrong but do solid spacer's only come in one size and the adjustment is made with the shims? I have never used a solid spacer before but have heard of them.
The aftermarket solid spacer kits come with one solid spacer and various shims to obtain the correct thickness. They are better than a crush sleeve but a real pain. You can measure the thickness of each individual shim, then the stacked thickness always seems to be different by usually 0.0005". That small amount makes a difference. The original is a one piece spacer of the correct length.
Well, after I finish fabricating a lower cowl on my Fairlane (since no one makes aftermarket repair patches or cowl for this car) I need to tackle rebuilding this rear. I found it on Craigslist for $50.
$50, that's a good price. From the ring gear bolts it looks like an original traction-loc. At least you made some type of fixture to hold it. More than I did.
Did your Yukon gear set indicate where they were made? And how long ago did you purchase them? I only ask because I've noticed Yukon uses the same part numbers as Motives lowest end line of gears (made in China) and some generic house brand gears. I also, found a Jeep forum where a person ordered Yukon gears only to find out Yukon packaging stated "Made in China".
I know gears seem to be from China, India, or Italy. US Gear claims USA made, but doesn't indicate that applies to all their products. From looking at part numbers and pricing I'm thinking US Gear only manufacturers their high end race stuff in the USA and imports their lower end street/performance stuff.
I made the fixture quite some time ago and helps hold the differential in place and makes it a little easier when setting the backlash. It actually bolts to my bench so no worries of it falling off. I also made it with movable ears so it accommodates both 8 and 9 inch differentials.
I am not sure yet if it is an equa-lock or traction-loc. I think the only way to tell is to crack open the carrier and look at the clutch plates on the inside. I believe the traction-loc's have 4 and the equa-lock's have 3 clutch plates or something like that. Although, I would prefer it to be a traction-loc for $50 I will gamble on the pot-luck. I believe someone has previously rebuilt this carrier since there are a couple mismatched ring gear bolts. Also, just by feel, I can tell there is way too much backlash. It has original Ford 3.50 ring and pinion gears and they look to be in good shape. Not sure if I will use this ratio or not. Since, I don't like to have too many things going on at one time I will start rebuilding it once my cowl is welded back onto my Fairlane.
I believe I purchased the Yukon gears about 5 years ago and if I am a betting man I didn't save any of the packaging....not even the Yukon sticker in the box!
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