I was wondering if maybe a Moly-based additive would help in that department - same question for the gearbox & tfr box too ??
Roy
Lubricate that racket away?
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Roy Gardiner
- Posts: 56
- Joined: Sun Jun 27, 2004 12:59 am
- Location: Hampshire, England
Lubricate that racket away?
Has anyone experimented with different lubes for the hub reduction gears in an effort to reduce their howling on the road?
I was wondering if maybe a Moly-based additive would help in that department - same question for the gearbox & tfr box too ??
Roy
I was wondering if maybe a Moly-based additive would help in that department - same question for the gearbox & tfr box too ??
Roy
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Philip Raymond
- Posts: 8
- Joined: Tue Sep 13, 2005 3:38 pm
Lube ???
Roy,
Not trying to "rain on your parade"....from my limited experience the portals are relatively and surprisingly quiet (for straight cut gearing), and generally need little attention, acoustically speaking. I suggest swapping off the Trellborgs or other aggressive and perhaps noisy tires for something you know to be quiet (like Goodyear Wrangler AT) and check the noise again. If it persists and you see some oil seeping or actual bearing spinning from the top needle bearing (it’s the cap looking like thing directly opposite the axle end on the inside of the rear portals and on top of the portal external axle stub) for the rear noise, or for the fronts (beside the portal innards) you need to consider a “singin birf”. Either sign means that that portal is not running normally and should be further investigated. A caveat is that I have only experience with lower mileage(< 50 Kmiles) portals and trucks. Perhaps as they get older they hum more. Also check the portal drain plug which have strong magnets built into them for excessive metal shaving or large metallic bits.
Good Luck.
Not trying to "rain on your parade"....from my limited experience the portals are relatively and surprisingly quiet (for straight cut gearing), and generally need little attention, acoustically speaking. I suggest swapping off the Trellborgs or other aggressive and perhaps noisy tires for something you know to be quiet (like Goodyear Wrangler AT) and check the noise again. If it persists and you see some oil seeping or actual bearing spinning from the top needle bearing (it’s the cap looking like thing directly opposite the axle end on the inside of the rear portals and on top of the portal external axle stub) for the rear noise, or for the fronts (beside the portal innards) you need to consider a “singin birf”. Either sign means that that portal is not running normally and should be further investigated. A caveat is that I have only experience with lower mileage(< 50 Kmiles) portals and trucks. Perhaps as they get older they hum more. Also check the portal drain plug which have strong magnets built into them for excessive metal shaving or large metallic bits.
Good Luck.
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Roy Gardiner
- Posts: 56
- Joined: Sun Jun 27, 2004 12:59 am
- Location: Hampshire, England
Transmission/tyre noise
Hi Phillip,
Yes, my own experience (albeit only with Haflingers) would confirm the relative quiet of hub reduction gears, but as the C3's are so much bigger (not to mention transmitting 5 times the torque!) I was unsure.
I still plan to give them a good dose of Molyslip - can't hurt!
With the 6 wheeler I'm aware of several noise sources, in most obvious order :
A. Mechanically driven fan (revs dependent)
B. Tyre noise (speed dependent) not as bad as I had expected with the military Goodyears' on/offroad open tread pattern
C. Transmission noise (speed dependent) this doesn't really start until 40kph is reached and is then harmonic (wah wah type sound) but lessens over 90kph (or just drowned out in the general cacophony
).
C. is the worst culprit in the NVH scenario in my vehicle, I wonder if balancing the prop shafts would effect an improvement?
Has anyone here balanced their props? Can I run the vehicle with either the front or rear-most prop removed safely (i.e. no nasty transfer box implications 'a la G Wagon') in a process of noise elimination?
Roy
Yes, my own experience (albeit only with Haflingers) would confirm the relative quiet of hub reduction gears, but as the C3's are so much bigger (not to mention transmitting 5 times the torque!) I was unsure.
I still plan to give them a good dose of Molyslip - can't hurt!
With the 6 wheeler I'm aware of several noise sources, in most obvious order :
A. Mechanically driven fan (revs dependent)
B. Tyre noise (speed dependent) not as bad as I had expected with the military Goodyears' on/offroad open tread pattern
C. Transmission noise (speed dependent) this doesn't really start until 40kph is reached and is then harmonic (wah wah type sound) but lessens over 90kph (or just drowned out in the general cacophony
).C. is the worst culprit in the NVH scenario in my vehicle, I wonder if balancing the prop shafts would effect an improvement?
Has anyone here balanced their props? Can I run the vehicle with either the front or rear-most prop removed safely (i.e. no nasty transfer box implications 'a la G Wagon') in a process of noise elimination?
Roy
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Philip Raymond
- Posts: 8
- Joined: Tue Sep 13, 2005 3:38 pm
More NVH
Roy,
A man after my own heart and a quick study!
A. Punt the fan.
B. Trellborgs are cheap but real noisy. Try Michelinn XS's or the quietest and most applicable for on-off road use (IMHO) the Goodyear Wranglers. You'll be amazed at the difference.
C. Chances are it will be the rear drive shaft. Balancing technology in the 70’s was not as accurate as today. I’d have it rebalanced and perhaps change over to a newer greasless fitting eliminating the soon to fail rubber boot, and for the cost I’d upgrade the universal joints while I was at it, over all a relatively small investment for a large comfort and functional improvement.
D. I have both run and flat towed C3’s without a front drive shaft without any mechanical ramifications.
Cheers,
A man after my own heart and a quick study!
A. Punt the fan.
B. Trellborgs are cheap but real noisy. Try Michelinn XS's or the quietest and most applicable for on-off road use (IMHO) the Goodyear Wranglers. You'll be amazed at the difference.
C. Chances are it will be the rear drive shaft. Balancing technology in the 70’s was not as accurate as today. I’d have it rebalanced and perhaps change over to a newer greasless fitting eliminating the soon to fail rubber boot, and for the cost I’d upgrade the universal joints while I was at it, over all a relatively small investment for a large comfort and functional improvement.
D. I have both run and flat towed C3’s without a front drive shaft without any mechanical ramifications.
Cheers,
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Roy Gardiner
- Posts: 56
- Joined: Sun Jun 27, 2004 12:59 am
- Location: Hampshire, England
Re: More NVH
Philip Raymond wrote:
> A. Punt the fan.
First job!
> B. ....try... the quietest and most applicable for on-off road use (IMHO) the Goodyear Wranglers. You'll be amazed at the difference.
I'll check and see if we can get the required size (37" seems about right with no diff changes - good job we're lowering the C of G with the camper shell!) in the UK.
> C. Chances are it will be the rear drive shaft. Balancing technology in the 70’s was not as accurate as today. I’d have it rebalanced and perhaps change over to a newer greasless fitting eliminating the soon to fail rubber boot, and for the cost I’d upgrade the universal joints while I was at it, over all a relatively small investment for a large comfort and functional improvement.
I'm goiing to whip the front and rear-most shafts off and drop them into my local propshaft specialists for an 'update' as you describe. They built the props for my Chevy/Range Rover convertible from scratch and did a lovely job for reasonable money.
I never mess with props after one we made up for a Ford V6 engined Austin Champ we built and raced let go at 60 mph! an underwear-ruining experience, not to be repeated.
Roy
D. I have both run and flat towed C3’s without a front drive shaft without any mechanical ramifications.
Cheers,