Trailers by Indespension

[Avocet]

I think the overheating problem if over-packed, applies to the grease rather than the bearings. As has been said, it gets too thin and runs out, or fails to properly lubricate the rolling elements. Clearly, it's all very "rule of thumb" - you can get away with more grease if you're only doing short distances at low speeds. The other thing is that grease has probably improved since that was the rule, and can now handle much higher temperatures before turning liquid. Lastly, centrifugal force being what it is, it's important to get the grease in between the rollers and the cage - otherwise, as the wheel rotates, it all gets "centrifuged" away from the areas it's supposed to lubricate.

 

[Beyondhelp]

Have to say I don't agree with this. I cannot see how there is such heat generated it would be beyond the melting point of the grease. Mine I cant say even got warm after a 260 mile trip at allowed speeds across the south UK with bearing savers thus packed and under pressure.

 

[gljnr1983]

I don't understand what you are saying.
In the picture the bearing race is packed with grease. There is a bit on the shaft. The other bearing is packed with grease. The gap between them is empty and there is no extra in the dust cap.
You can see a grease nipple on the hub which would pack grease into the cavity between the bearings. I never use that. Instead I take the hub off and put grease in manually if it needs some. Better to wipe away contaminated grease and refresh rather than to just add more grease.
If the hub is full of grease within a few miles it will have warmed up and squirted out of either the hole in the dust cap if there is one or blown past the grease seal.

So is the nipple on the hub a design fault? That would mean having to dismantle the hub and bearings ,clean with solvent and blow the solvent and particles off all surfaces with compressed air every time you want to repack and avoid grease contamination, wiping with a cloth just pushes the contaminated grease into the workings. I would call this over kill,especialy if you dunk in the salt every weekend.Also you should not get contaminated grease if you use the nipple to repack that water loving area between the bearings after every dunking. Would the engineer that designed these hubs not have put these nipples in if they were no use.You are rite about the grease heating up and expelling the excess grease which should leave the rite amount in there.

 

[Lakesailor]

You seem to have become very indignant on the designer's part.
No, I think the nipples are not much use there for the reason I expressed. If the grease has become contaminated with sea water new grease introduced in the void will not replace that in the bearings. I feel they are a hopeful design feature. I won't be using them.
Still. Be a boring world if we all thought the same thing.

 

[Jim@sea]

Of course after reading all this last year, this year I made the ususual mistake which boat buyers do in concentrating on the condition of the boat I was buying and ignoring the state of the trailer assuming that as there was grease everywhere that it had been serviced.
Untill after one wheel started to smoke and the grease ran out. And the brakes had locked.
So taking the hub off I found that the brake linings had detatched from the shoes and had jammed up. The second hub I took off part of a brake lining has detatched.
So obviously I am replacing all the shoes.
Morale of the story. Never Assume.

 

[BJ1]

Myths and legends?

I've read this thread with interest and a degree of mild amusement.

I've talked to an expert on bearing lube and he says that grease cannot and does not "generate heat" in a hub. The amount of friction between the 'layers' of rotating grease is miniscule. Bearing savers are an excellent investment as they keep the hub full of grease and under slight pressure, keeping out water.

I've towed boat trailers for over 40 years and have always packed the hubs completely. I've never had a hub heat up because I adjust the bearings properly. NOBODY has mentioned this at all. Taper roller bearings are designed to have a small amount of play NOT to be "tightened" as one post says. There should be no preload at all on these bearings, unless they are running in an oil bath such as in a gearbox. If you don't believe this then talk to bearing manufacturers. As an example, VW aircooled buses have greased taper rollers in the front hubs and the service manual specifies the play at the wheel rims should be around 0.3mm. Many an owner has "tightened" these bearings and cooked the races within 50 miles. I suspect the same is true of trailer bearings.

My advice is to adjust your trailer bearings so there is a very small amount of free play. This is not easy because on Indespension units there is often only one hole for the locking split pin, which gives only coarse adjustment. I drill another hole to give better adjustment options.

I would also add that too many trailers are towed at (illegal) speeds, way above what they were designed for. 50 mph should be the aim, not the 80 mph I sometimes see on motorways. Try stopping in a hurry with a boat on the back - the tail will wag the dog big time.

 

[VicS]

I've read this thread with interest and a degree of mild amusement.

I've talked to an expert on bearing lube and he says that grease cannot and does not "generate heat" in a hub. The amount of friction between the 'layers' of rotating grease is miniscule. Bearing savers are an excellent investment as they keep the hub full of grease and under slight pressure, keeping out water.

I've towed boat trailers for over 40 years and have always packed the hubs completely. I've never had a hub heat up because I adjust the bearings properly. NOBODY has mentioned this at all. Taper roller bearings are designed to have a small amount of play NOT to be "tightened" as one post says. There should be no preload at all on these bearings, unless they are running in an oil bath such as in a gearbox. If you don't believe this then talk to bearing manufacturers. As an example, VW aircooled buses have greased taper rollers in the front hubs and the service manual specifies the play at the wheel rims should be around 0.3mm. Many an owner has "tightened" these bearings and cooked the races within 50 miles. I suspect the same is true of trailer bearings.

My advice is to adjust your trailer bearings so there is a very small amount of free play. This is not easy because on Indespension units there is often only one hole for the locking split pin, which gives only coarse adjustment. I drill another hole to give better adjustment options.

I would also add that too many trailers are towed at (illegal) speeds, way above what they were designed for. 50 mph should be the aim, not the 80 mph I sometimes see on motorways. Try stopping in a hurry with a boat on the back - the tail will wag the dog big time.

I'd not like to comment on the argument about grease not generating heat. The manuals for vehicles I have owned have all emphasised that the bearings should not be over-packed.

The method I have adopted for tightening taper roller bearing hubs is to tighten firmly while spinning the wheel .. to ensure the bearings are fully bedded into position. Then back off until just slack and then re- tighten the nut with my fingers. That seems to produce just about the right amount of free play.

 

[Niander]

I've read this thread with interest and a degree of mild amusement.

I've talked to an expert on bearing lube and he says that grease cannot and does not "generate heat" in a hub. The amount of friction between the 'layers' of rotating grease is miniscule. Bearing savers are an excellent investment as they keep the hub full of grease and under slight pressure, keeping out water.

I've towed boat trailers for over 40 years and have always packed the hubs completely. I've never had a hub heat up because I adjust the bearings properly. NOBODY has mentioned this at all. Taper roller bearings are designed to have a small amount of play NOT to be "tightened" as one post says. There should be no preload at all on these bearings, unless they are running in an oil bath such as in a gearbox. If you don't believe this then talk to bearing manufacturers. As an example, VW aircooled buses have greased taper rollers in the front hubs and the service manual specifies the play at the wheel rims should be around 0.3mm. Many an owner has "tightened" these bearings and cooked the races within 50 miles. I suspect the same is true of trailer bearings.

My advice is to adjust your trailer bearings so there is a very small amount of free play. This is not easy because on Indespension units there is often only one hole for the locking split pin, which gives only coarse adjustment. I drill another hole to give better adjustment options.

I would also add that too many trailers are towed at (illegal) speeds, way above what they were designed for. 50 mph should be the aim, not the 80 mph I sometimes see on motorways. Try stopping in a hurry with a boat on the back - the tail will wag the dog big time.

Nice first post and so right about those Taper roller bearings...
Btw i have a T25 VW Bus

 

[Avocet]

I agree about there needing to be a tiny bit of free play in a pair of opposed taper rollers, but they DO generate heat - even when correctly adjusted. Not much, but definitely some. Even a light (unbraked) dinghy trailer's hubs will feel a bit warm to the tough after a run. I imagine that's a combination of bearing friction, seal friction and viscous "shear" in the grease. Pretty much any fluid being agitated will get warmer. I don't see why grease should be any different. I expect that the main reason for the recommendations not to over-pack with grease are more to do with allowing some room for expansion with temperature, so that it doesn't get pushed past the seals.

 

[sailing-girl]

I have a problem similar to fifi.

I was asked to purchase a trailer for a safety boat for use in our small sailing club. The idea is thatit would launched by hand by a few sailors during dinghy sailing sessions. The Coaster Swing Mini was recommended for the job. However, since it will be owned by a sailing club, maintenance could be a problem and the possiblity of problems with the bearings is a concern.

Would anyone have a recommendation for another type of lauch trolley/trailer for a boat of this type?

 

[alahol2]

I have a problem similar to fifi.

I was asked to purchase a trailer for a safety boat for use in our small sailing club. The idea is thatit would launched by hand by a few sailors during dinghy sailing sessions. The Coaster Swing Mini was recommended for the job. However, since it will be owned by a sailing club, maintenance could be a problem and the possiblity of problems with the bearings is a concern.

Would anyone have a recommendation for another type of lauch trolley/trailer for a boat of this type?

View attachment 28888View attachment 28889

If you are not going to trail the boat/trailer on the road then a plain bearing would be perfectly adequate. In other words a big launching trolley.

 

[Lakesailor]

Yes. Keep the road trailer for road trips and/or moving other boats.

Something like this......

http://www.cadkat.com/BigFoot_V_RIB...ith_broad_V-support-load_capacity_150_kg.html I'm sure there are British manufacturers of similar product. If you have a hard slip the big tyres may be a bit OTT.

To be honest, I would think about a secondhand trailer and accept that the bearings will need changing every year.

 

[Seajet]

+1 for simple bush type axles, no bearings.

Is there a ' bosun ' at your club to carry out maintanance ? Also keep an eye on insurance, which can make mountains out of molehills, club members need to sign disclaimers saying they have their own cover.

 

[William_H]

Here in Oz boat trailers are big business. Bearing Buddies for tapered roller bearings are sold which have a moving cap to the bearing cap. This is spring loaded and has also a grease nipple. The idea is that you fill the entire cavity with grease to the point where the spring loaded cap is half compressed. This means there is always a little positive pressure in the cavity. As the bearing heats up the cap will move out to adjust to the higher pressure. When the bearing is dunked in the water the spring moves the cap in to keep a positive pressure so water is not sucked into the bearing.
http://www.biasboating.com.au/Bearing_Protectors_p/3928.htm
I have to disagree with Vic analogy to the physics experiment with work heating water. I think the bulk of the grease will remain static with a shear surface at the bearing. There will not be very much stirring of the grease. I think just friction of the bearing will provide more heat.
We see very few launching trolleys Only for Laser or similar off the beach boats. Any rib larger than 8ft will have a road trailer which is dunked. Most owners will simply accept that boat trailers that are dunked must be given a lot of maintenance especially brakes and bearings. For me maintenance is obligatory after every dunking. I think the OP was simply ignorant and thought his new trailer was to be treated like his new car or caravan. Perhaps Indespension were short on the harsh details of boat trailer ownership.
Anyway I don't use the Bearing Buddies described I just pull the bearing after every dunk clean it out if water has got in and regrease if necessary. It only takes minutes. good luck olewill
PS look at an OZ chandlers catalogue . A huge part dedicated to trailer equipment.