How to determine bearing size

[The Incredible Hull]

Hi Raiders,

I was looking at replacing my trailer bearings, for the first time.

I've done a bit of research, have a fair idea on what to do.

Have 3 questions, hoping you guys can assist with:

1. How do I measure what size bearing I need? (without taking the bearing out, I want the new part with me to swap out straight away)

2. Has anyone fitted Spindle Seals? I hear this is good, when using Bearing mates(which I have fitted), to prevent the back seals from leaking

3. The space in between the inner and outer bearings, does that get filled up with grease too?

Cheers guys.

Dave

[Fab1]

Hi Raiders,

I was looking at replacing my trailer bearings, for the first time.

I've done a bit of research, have a fair idea on what to do.

Have 3 questions, hoping you guys can assist with:

1. How do I measure what size bearing I need? (without taking the bearing out, I want the new part with me to swap out straight away)

2. Has anyone fitted Spindle Seals? I hear this is good, when using Bearing mates(which I have fitted), to prevent the back seals from leaking

3. The space in between the inner and outer bearings, does that get filled up with grease too?

Cheers guys.

Dave

Here's some info that may help.

Axle length is measured from tip to tip of bare Axle

Specifications

39mm Round Axles - 750kg maximum operating weight. Runs LM (Holden) bearings.

40mm Square Axles - 1000kg maximum operating weight. Runs LM (Holden) bearings.

45mm Square Axles - 1400kg maximum operating weight. Runs SL (Ford) bearings.

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Bearings

Bearings are used to match the type of axle you have NOT the type of stud pattern you have. Eg. If you have Ford wheels, but your axle is Holden, then you need hubs with a Ford stud pattern and Holden bearings.

LM (Holden bearings) suit 39mm Round & 40 mm Square Axles

· Outer (small) bearings # LM 11910 - Cup

# LM 11949 - Bearing

· Inner (large) bearings # LM 67010 - Cup

# LM 67048 - Bearing

SL "Slimline" (Ford bearings) suit 45mm Square Axles

· Outer (small) bearings # L 12710 - Cup

# L 12749 - Bearing

· Inner (large) bearings # L 68110 - Cup

# L 68149 - Bearing

The best way to work out what bearings you need is to measure the flat part of your axle stub where the bearings sit.

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Stud Patterns / PCD

(for all hubs / hubdrums / hubdiscs)

Stud patterns are worked out using the PCD measurement. This is the distance from one side of the stud circle to the other (see picture below). Many wheels from different makes and models have the same PCD, ie. even though a stud pattern is referred to as 'Ford', it also matches Mitsubishi, Mazda, Toyota etc.

Ford - 1/2" UNF studs - 5 Studs - PCD 114.3mm - 68mm from stud to stud

Holden HT / Early Holden - 7/16" UNF studs - 5 Studs - PCD 108mm - 65mm from stud to stud

Holden HQ - 7/16" UNF studs - 5 Studs - PCD 120.6mm - 72mm from stud to stud

Commodore - 7/16" UNF studs - 5 Studs - PCD 120mm - 72mm from stud to stud

Gemini - 7/16" UNF studs - 4 Studs - PCD 100mm - not available in braked kits

Toyota - 7/16" UNF studs - 4 Studs - PCD 114.3mm - not available in braked kits

Mini - 7/16" UNF studs - 4 Studs - PCD 101.6mm - 5 1/2" hub - not available in braked kits

Landcruiser 80 series - 1/2" UNF studs - 6 Studs - PCD 139.7mm - 70mm between studs

Landcruiser 100 series - 9/16" UNF studs - 5 Studs - PCD

________________________________________________________________________________

Chrome Mag & Lug Nuts

Available sizes:

Lug Nuts - 1/2", 7/16", 12 x 1.25mm

Mag Nuts - 1/2", 7/16", 12 x 1.25mm, 12mm x 1.5mm

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Why use bearing buddies with your hubs?

Because water enters your grease & bearings under normal conditions, and without bearing buddies, air pockets are created within the hub, and get hot and expand.

As you drive down the boat ramp, the bearings enter the cold water. The air and grease inside the hubs shrinks and sucks in water. The problem with this is that the water then contaminates the grease, turning it into a hard, gritty, muddy muck. This will DESTROY your bearings.

And no one wants to be stuck on the side of the road, in the middle of nowhere, wishing they had Bearing Buddies.

When using bearing buddies, drive to the boat ramp, pump grease into the bearing buddies until it expels grease out the rear seal. It is spring loaded so it keeps a positive pressure and is solid with grease inside your hub, which in turn helps to stop water entering.

Bearings will still need maintenance, but just not as often, the savings you get back from bearing buddies, in grease and labour, will pay for itself in one sevice.

Cheers.

Edited December 7, 2015 by Fab1

[big Neil]

That's a very comprehensive and informative explanation of trailer bearing /wheel set ups FAB 1. Thank you. Big Neil.

[antonywardle]

Don't forget, the rule of thumb.

If you can fit your small bearing on your thumb then it

is most like a ford, if not then its a holden.

Can't remember where I read that but it seems to be true.

I just got some new ford hubs with holden bearings

lots of fun doing the packing.

[shakey55]

Very informative. I to have learnt something new today. Well done [emoji818]️

Sent from my iPad using Tapatalk

[Nolongeramember]

Awesome information Fab thanks.

Just to add to one of his questions, yes you fill the space in between the bearings with grease.

[fisherman666]

Great information!

Sent from my GT-I9100 using Tapatalk

[The Incredible Hull]

Thanks again Fab, you're a legend!

[Fab1]

Glad this helped you guys and just one more thing incredible hull,In regards to your question 2 those are known as speedy sleeves which are used for stub axles in poor condition which are usually pitted to give them a fresh running surface for the seal to prevent leaks.But let me tell you the #1 culprit for causing leakage at the seal is the person on the end of the grease gun pumping away merrily.Grease doesn't compress,when you pump grease into a hub through the bearing buddy once the hubs cavity has reached capacity and you keep pumping,guess what?The grease will act like a hydraulic ram and look for the path with least resistance,the rear seal.With bearing buddy's you want to pump grease into them until the spring and washer start to compress a few millimeters no more and stop.you should be able to move it with your thumb.But keep pumping regardless of if you have speedy sleeves or not you will blow your seal out the back of the hub or the bearing buddy itself fall off(I've seen this happen at the ramp)Grease exerts tremendous force when it has now where to go and is pressurised.

I use grease to remove spigot bearings when doing clutches on cars,it pulls them right out of the back of the crankshaft.

Cheers.

[big Neil]

What do you think of the oil filled bearing on a light trailer? My mate, who is a diesel mechanic, swears by them and uses Foreys oil in his. He's never had any problem with wheel bearings. What's your thoughts? Big Neil.

[Fab1]

What do you think of the oil filled bearing on a light trailer? My mate, who is a diesel mechanic, swears by them and uses Foreys oil in his. He's never had any problem with wheel bearings. What's your thoughts? Big Neil.

I think oil filled bearings on any trailer is superior to grease as the lubricating properties of having the bearings in a constant bath of oil simply can't be matched by grease and the bearings do run cooler.

My family has horses and I have fitted dura hub extreme running a combination of penrite 80/90 gear oil and Mobil grease to our float as well as others I work on.

Some of those floats are doing trips from Sydney-Melbourne,Sydney-Brisbane and back without issue going to various events.

Having said that its imperative that with any oil filled system especially that the machined areas on the axle spindle is perfectly smooth and round for a perfect seal when installing the seal.

Having said that my boat came with bearing buddy's (The cheap ones) and since I bought it in 2011 I have serviced the bearings yearly without ever having an issue.What really kills bearings is saltwater getting into them combined with short trips and the boat sitting idle with it's weight on the axles in my opinion.

Very soon I will be redoing my trailers bearings and am thinking of putting up a post on various ways of removing and replacing them that should help some of the guys willing to have a go.

If there's one skill all boaters should have is how to inspect,remove and replace bearings in my opinion as you wouldn't believe how many people I've helped over the years with bearing failure sitting on the side of the road.

Stay tuned.