Nylok nuts

[gt14rider 1,158]

Hi all. Question  can you use a nylok nut in stead of a prevailing torque lock nut in the differential bolts.

Upgrade to grade 8 bolts

[ebinmaine 78,382]

19 minutes ago, gt14rider said:

Question  can you use a nylok nut in stead of a prevailing torque lock nut in the differential bolts

 

 

I did. Several times...

[oldlineman 1,680]

And maybe some Loctite, for extra confidence, don't need them nuts working off, very bad things happen.  

[pfrederi 20,325]

I use these

better grip than nylock

They have a grade 9 version which is what i used in my D200 also had to get Gr9 bolts

 

 

[ri702bill 11,907]

32 minutes ago, oldlineman said:

And maybe some Loctite, for extra confidence, don't need them nuts working off, very bad things happen.  

NOT an application for a USED nylok nut. They form (displace??) a thread into the nylon portion the frist time used - that is how they get their grip. A re-used one has much less retention.

Totally agree that bad things (think expensive) happen when the nut works loose..... 

Edited Tuesday at 07:09 PM by ri702bill

[953 nut 65,378]

18 hours ago, gt14rider said:

can you use a nylok nut in stead of a prevailing torque lock nut in the differential bolts.

Upgrade to grade 8 bolts

You CAN, but you shouldn't.

We all know two things about the pond family philosophy toward building Wheel Horses, they built a quality product and they were very thrifty (not to be confused with being cheap).

The flex top nuts used by Wheel Horse cost $ 1.08 today as compared to the Nylok nuts of the same size at $ 0.28 each at McMaster-Carr. If the Ponds were willing to spend about four times as much for these nuts there had to be a good reason for doing it.

 

Flex-Top Locknuts for Heavy Vibration

Image of Product. Front orientation. Locknuts. Flex-Top Locknuts for Heavy Vibration.

The top section of these nuts expands to grip the screw on all sides for a stronger hold than both nylon-insert and distorted-thread locknuts. They’re often used in equipment with constant, vigorous vibration, such as engines. These locknuts are reusable a handful of times, but the holding power decreases with each use.

Steel

These locknuts have equivalent strength to Grade 8 and Class 10 steel nuts. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.

Black-Oxide Steel

  

3/8"-24            9/16"   15/32" 5          94820A430      5.42    

 

 

Nylon-Insert Locknuts

Versatile yet economical, these are the most commonly used locknuts. The nylon insert grips the screw to prevent loosening from moderate vibration without damaging threads. However, the insert may become brittle if exposed to high temperatures. These locknuts are reusable a handful of times, but the holding power decreases with each use.

Zinc-Yellow-Chromate-Plated Steel

 

3/8"-24            9/16"   29/64" SAE Grade 8    185      —         20        97135A235      5.71    

 

[Gasaholic 364]

Problem with nylock nuts is heat and age with exposure to gear oil differentials can get quite warm and thermal expansion can distort the nylon insert over time it loosens - like others said, not something to have happen in those transmissions...  Use the correct locking nuts (even $2 extra per nut over 8 nuts is still much cheaper insurance than having to buy new gears, or worse, transaxle case) we always also added red loctite to the nuts when rebuilding those, even with those prevailing torque locknuts. 

[ebinmaine 78,382]

I'd be extremely curious to know if Wheel Horse used a certain type of locking nut for the entire history of their manual transmissions. I put Nylock nuts back in place because that was what was in a bunch of the ones I've taken apart.

 

[Achto 31,628]

4 hours ago, 953 nut said:

The flex top nuts used by Wheel Horse cost $ 1.08 today as compared to the Nylok nuts of the same size at $ 0.28 each at McMaster-Carr. If the Ponds were willing to spend about four times as much for these nuts there had to be a good reason for doing it.

 

Depending upon the year of the tractor it may have also been an availability thing.

 

Nyloc nuts (nylon insert locknuts) began becoming widely available in the 1950s to early 1960s, following their invention in 1931 and increasing adoption in the post-war industrial boom. While early versions existed, production increased significantly by companies like Abbott Interfast (beginning 1964) as they became standard in industries needing vibration resistance, such as automotive and aerospace. 

RS Components +4

• Invention: Invented in 1931 by United Shoe Machinery.
• Early Adoption: While invented earlier, widespread industrial usage grew throughout the 1950s.
• Production Boom: The 1960s saw widespread availability, with manufacturers like Abbott starting high-volume production in 1964.
• Initial Use: Primarily used to replace expensive, traditional methods of locking nuts, such as two nuts on a single bolt.

[WHX?? 56,180]

22 hours ago, ebinmaine said:

 

 

I did. Several times...

Oh oh 

I did use red Loctite with the nylocks as well and the threads were super clean. 

[ebinmaine 78,382]

9 minutes ago, WHX?? said:

Oh oh 

I did use red Loctite with the nylocks as well and the threads were super clean. 

 

I ALWAYS use new grade 8 bolts with new grade 8 nyloc nuts. One use. 

 

 

[WHX?? 56,180]

2 minutes ago, ebinmaine said:

 

I ALWAYS use new grade 8 bolts with new grade 8 nyloc nuts. One use. And torqued to the value for that size hardware. 

 

 

There finished that for ya ... 

[ebinmaine 78,382]

On 4/29/2026 at 9:08 AM, Gasaholic said:

Problem with nylock nuts is heat and age with exposure to gear oil differentials can get quite warm and thermal expansion can distort the nylon insert over time it loosens - like others said, not something to have happen in those transmissions...  Use the correct locking nuts (even $2 extra per nut over 8 nuts is still much cheaper insurance than having to buy new gears, or worse, transaxle case) we always also added red loctite to the nuts when rebuilding those, even with those prevailing torque locknuts. 

 

 

I looked at a couple of the differentials on my parts shelf.  A limited slip from a 6 speed and an open 8 speed diff. 

Both had nyloc nuts. 

Original? 

I dunno....