Part 3- Driveshaft Maintenance

Part 3 - Driveshaft maintenance.

Driveshafts should be carefully inspected and lubricated (as applicable - some components, and even some entire driveshafts are non-serviceable and cannot be re-greased) at recommended original equipment vehicle manufacturers’ service intervals and/or at Spicer recommended lubrication intervals OR you can use my recommendations, which are:

Severe use (wet, muddy, or high-torque carrying use, extreme low gears (80:1 and lower), large tires(35" and over)) 3000 miles, 2 months, or 250 Hrs, whichever comes first

Moderate use (dry conditions, on and off road use) 5000 miles, 3 months, 500 Hrs, whichever comes first

Mild use (mostly street duty - some off-road) 8000 miles, 6 months, whichever comes first

Before undertaking any of these procedure, be sure to read and heed the section on Safety.

Driveshaft Safety

CAUTION

Caution – Under no circumstances should individuals attempt to perform driveline service and/or maintenance procedures for which they have not been trained or do not have the proper tools and equipment. See warning below.

WARNING

WARNING
Failure to release all parking brakes and failure to place transmission in neutral can result in torque being applied to the driveshaft. Disconnecting a driveshaft with applied torque can result in property damage, serious personal injury or death.

WARNING
Failure to take commonsense, precautionary measures when working on a vehicle or other machinery could result in property damage, serious personal injury or death. In order to avoid property damage, serious personal injury or death, you must:

1. ALWAYS wear safety glasses when performing maintenance or service. Failure to wear safety glasses can result in personal injury and/or partial or complete vision loss.
2. NEVER go under a vehicle while the engine is running. Be sure the vehicle’s engine is off, and keys are removed from ignition.
3. NEVER go under or work on a vehicle that is not on a level or flat surface.
4. NEVER work on a driveshaft without blocking the vehicle’s wheels and releasing all parking brakes.
5. NEVER lift a vehicle without the appropriate weight-rated, vehicle-support equipment.
6. NEVER REMOVE a driveshaft from the vehicle without keeping the vehicle’s transmission in neutral.
7. CAUTION – Driveshaft assemblies can be very heavy. Be sure to use proper lifting techniques when handling driveshafts. More than one person may be needed when handling driveshaft assemblies.
8. ALWAYS use support straps to prevent the driveshaft from falling out of vehicle during the removal and installation process.
9. NEVER heat components or use sledgehammers or floor jacks to remove the driveshaft from vehicle.

Note – For driveshaft applications that have pillow blocks, dampers, parking brakes or retarders, refer to these component manufacturers’ or the original equipment vehicle manufacturers’ service manuals for proper procedures.

Note – The following procedures are to be performed prior to any lubrication of universal joints or slip members.
The addition of lubricant can mask the looseness in a component that is beginning to show wear and may be in need of replacement.

Note - The following pics are taken from Spicer's Heavy Duty Driveshaft manual (trucks over 30,000lbs) so the driveshafts themselves will appear huge, compared to what we 4x4 users are used to.

To properly inspect the driveshaft, you need to block the vehicles wheels, set the parking brake, put the transmission in Neutral (N), and the transfer case in 2wd. If you have a selectable locker or lockout manual hubs, unlock them. This is all important because you want to make sure that there is no drag or pressure or bind on the driveshaft that can mask wear and sloppiness during your inspection.

INSPECTING END FITTINGS

Visually inspect all input and output end-fitting (yoke) retaining nuts, clips, or bolts for any gaps between mating surfaces. If gaps are present, consult transmission, axle or transfer case original equipment manufacturers’ service and maintenance manuals for proper fastener specifications.

Visually inspect for damaged bearing retainers or stamped straps, loose bearing retainer bolts or strap bolts, loose companion flange bolts and nuts, loose or missing spring tabs or spring tab bolts, damaged tangs on end fittings, damaged or missing snap rings, and rotating bearing cups. If any of these situations are evident, replacement of the components is necessary.

Check for excessive looseness across the ends of the universal joint bearing cup assemblies and trunnions. Take hold of the inboard yoke on the driveshaft with both hands. Try to move yoke vertically and horizontally. (See photo left above.) There should be less than .006 in. (.15mm) movement in the universal joint kit relative to the inboard or outboard yokes. If looseness is greater than .006 in. (.15mm), the universal joint kit must be replaced.

INSPECTING UNIVERSAL JOINTS

Visually inspect all universal joint kits in the driveshaft assembly. Make a careful inspection of the caps of the u-joints where they are held captive in the end fittings (yokes). Look to see if the caps are polished or shiny. If they are, it indicates that the cap is spinning in the bore, and the u-joint and attachment hardware will have to be replaced.

There are 3 types of U-joints used in driveshafts:

1. Relubable style
2. Permanently Lubricated Plug Style
3. Permanently Lubricated Net-Formed Style

Each requires slightly different inspection procedures

Relubable style

Check for the presence of all grease zerk (nipple) fittings. (See photo left). Grease zerk (nipple) fittings should not be missing, loose or fractured. If grease zerk fitting is loose, tighten to required specifications. If grease zerk fitting is fractured, replace grease zerk fitting and tighten to required specifications. If grease zerk fitting is missing, the entire universal joint kit needs to be replaced.

Permanently Lubricated Plug Style

Permanently lubricated plug style universal joint kits do not contain grease zerk fittings, only a plug. (See photo left) Make sure plug is not missing, loose or fractured. If the plug is loose, tighten to required specifications. If a plug is missing or fractured, the entire universal joint kit needs to be replaced.

Permanently Lubricated Net-Formed Style

Net-formed universal joints do not contain grease zerk (nipple) fittings or plugs and are not relubable (See photo left)

INSPECTING SLIP MEMBERS

Check the slip member assembly for excessive radial looseness. Using a dial indicator (or a very carefully calibrated eyeball :-), take hold of the tubing near the slip member with both hands and try to move vertically, up and down relative to the ground. There should be limited looseness in the slip member assembly. (See photo left) If looseness is greater than .012 in. (.30mm) as read on dial indicator, replacement of the slip member assembly is necessary.

Visually inspect for the presence of the grease zerk fitting, if applicable, on the slip yoke. (See photo left) Grease zerk fittings should not be missing, loose or fractured. If grease zerk fitting is loose, tighten to required specifications. If grease zerk fitting is missing or fractured, the slip members may need to be replaced. Be sure to follow above procedure for inspection of radial looseness in slip member assembly.

If slip member assembly is within acceptable limits as stated above install new grease zerk fitting and tighten to required specifications. Be sure to completely re lubricate slip member assembly with recommended lubricant.

INSPECTING TUBING

Check the driveshaft for bent or dented tubing, cracks, or failed welds. If any of these situations is evident, replacement of the complete driveshaft assembly or tube is necessary.

INSPECTING CENTER BEARINGS

Lubrication

Why?

Lack of proper lubrication is one of the most common causes of universal joint and slip member problems. In all of my experience, (and Jess will back me up on this too) the u-joints most likely to fail are the re greasable kind that haven't been properly lubricated frequently enough.

Proper re lubrication flushes the universal joints, thus removing abrasive contaminants from the bearings. Relubable slip members must also be adequately re lubricated to prevent slip member failure.

When?

First, on installation, regardless of if the joint is re lubable or not. Replacement universal joint kits contain only enough grease to provide needle roller bearing protection during storage. It is therefore necessary to completely lubricate each replacement kit prior to assembly into the yokes.

After initial installation, you can follow either your vehicle manufacturer's recommended intervals, Jess's recommendations, or follow my recommendations, which are:

Severe use (wet, muddy, or high-torque carrying use, extreme low gears (80:1 and lower), large tires(35" and over)) After every off-road trip, 3000 miles, 2 months, or 250 Hrs, whichever comes first

Moderate use (dry conditions, on and off road use) 5000 miles, 3 months, 500 Hrs, whichever comes first

Mild use (mostly street duty - some off-road) 8000 miles, 6 months, whichever comes first

How?

For the Universal Joints:

Using the recommended lubricant (see below) use a hand operated grease gun (air powered guns use to much pressure and can blow out seals and force contaminant in) and pump grease into the grease nipple until it flows out from all 4 bearing cap seals. You cannot over-grease a u-joint.

Note: If your shaft uses permanently sealed (non re lubable u-joints - don't attempt to disassemble them to re-lube them, and DO NOT attempt to use any of those sharp needle attachments designed for piercing seals to inject grease. You will only make things worse, and hasten their demise, as you will ruin the seals. Just leave them in there, and replace the whole thing when it wears out. If you find yourself dissatisfied with their life-span, consider trying the re lubable kind in future.

For the Slip Member:

 

If your driveshaft slip member has the grease nipple at the yoke end (like mine - yellow arrow in pic above) - cover relief hole (pic at left) and pump grease till it flows from under the dust cap (blue arrow in pic above).

For the CV assembly (if applicable).

 

Disconnect the CV head assembly from the vehicle so that you can access the recessed grease fitting in the CV assembly (yellow arrow). Using a needle attachment on your grease gun, pump grease into the fitting until it flows out freely.

THIS is critical. This is probably the single most neglected grease fitting on a 4x4. Long, smooth driveshaft operation demands proper and frequent lubrication. You wouldn't be too lazy to change the oil in your engine for 50 000 miles, so don't abuse your driveshaft that way either.

Important Note: High Angle Driveline is the ONLY company to offer a true HIGH ANGLE 1350 CV assembly that is re lubable for smooth operation and long-life. the others say it couldn't be done.......but they were WRONG! Jess has worked his magic - and it works, and it still brutally strong - anyone claiming otherwise is fooling themselves. This is reason enough to go to Jess for your driveshafts. Having that CV head assembly wear out prematurely because of improper service and ingress of contaminants (and if you use your 4x4 like I do, you WILL get water and mud and grit and dust in EVERYTHING!) would be a huge pain, and expensive to repair/replace!

With What?

Spicer recommends that the following requirements be met for any lubricant that will be used to service most vehicular, industrial and all auxiliary driveshaft applications.
• Use a good quality E. P. (extreme pressure) grease
• Timkin Test Load - 50 Lbs./23 Kg. minimum
• Meeting N.L.G.I.,* E. P., Grade 2 specifications
• Grease must have an operating range of
+325°F to -10°F (+163°C to -23°C)

*National Lubricating Grease Institute

GREASE COMPATIBILITY*
When greases made from different thickeners are mixed, the mixture may result in lower service performance or physical properties than either of the original component products.
This reduction in lubricant performance is called incompatibility. It may show up in any of several areas, such as:
1. Lower heat resistance;
2. Change in consistency, usually softening; or
3. Decrease in shear stability.
Mixtures which show none of these changes are considered compatible. Incompatibility is not always caused by the thickener, since each of the greases in the mixture is a complete package – thickener, fluid, and additives. Sometimes the thickener of one grease is incompatible with the fluid or the additives present in the second grease. If the mixture proves to be significantly softer, less shear stable, or less heat resistant than the original grease, the mixture shall be deemed incompatible. Incompatibility is best determined in service or in service related tests; it is not predictable. Certain thickener combinations often have been found unsatisfactory and are generally so recognized. These would include lithium and sodium greases and organo-clay and most soap greases. Contact your local lubricant supplier for grease compatibility information. To help reduce the effects of incompatible greases, make sure to thoroughly purge all four bearing seals on each universal joint with the new grease. Purge seals until the fresh grease is visible on the outside of all four bearing seals. It is recommended that all purged grease be wiped clean to prevent discharge into the general environment.

Did I do it right?

Ever wonder if you HAVE to get grease purging from all 4 bearing caps in a U-joint when lubricating it? Ever wonder why? The answer is "yes, you do, because otherwise you cannot be sure all bearings are fully lubricated and all foreign material and water is evacuated due to unequal seal pressures due to tolerance stack up in components." What the heck does that mean? It means, grease the joint until all 4 sealed purge! And if all 4 will not purge - relieve the pressure on the bearing caps that will not, and try again. The procedure is outlined below. If the joint still will not purge from all 4 seals - it must be replaced. See the Spicer Video on Proper U-joint Lubrication for the complete story.

Procedure for releasing universal joint bearing seal tension

Bearing strap / U-bolt style.

If striking lug ears does not cause purging, remove the retaining hardware from the affected bearing caps (follow removal procedure outlined below if required, making sure to mark driveshaft for phasing before removing any hardware) and unseat bearing cup assemblies from yokes (by tapping on yoke or bearing cup with a soft-faced hammer if required). Once the bearing cup assemblies are free, allow the driveshaft to rest on a. support strap. Remove snap rings in lug ears of the inboard bearing caps that are not purging Note – Spicer snap rings can be reused if they ARE NOT severely corroded or distorted. If corroded or distorted, replace used snap rings with new

Purging Inboard (captive in driveshaft yoke) Bearings

Apply a c-clamp around the outboard (those that seat in the pinion or T-case yoke) bearings. Apply grease gun pressure. Completely purge both inboard (those captive in the driveshaft yoke) bearings. See pic (purge inboard)

Purging Outboard (that connect to yokes) Bearings

If outboard bearings fail to purge, slightly loosen c-clamp and reapply grease gun pressure until both outboard bearings purge.

It may be necessary to unseat bearing cup assemblies by tapping on yoke or bearing cup with a soft-faced hammer. (See pic at left.) Once the bearing cup assemblies are free, collapse the driveshaft until both bearing assemblies clear the open end yoke cross holes. Allow the driveshaft to rest on support strap.

Once the driveshaft is free, remove the driveshaft from the support straps and take it to a work bench area.

Check all end yokes for looseness. Take hold of end yoke with both hands. Try to move it vertically and horizontally to feel any looseness. There should NOT be any looseness in the end yokes relative to the input or output shafts to which they are connected. If looseness is evident, the end yoke needs to be replaced.

Remove all internal and external snap rings.

Install new joints in shaft

Note – Spicer Life replacement universal joint kit bearing assemblies contain only enough grease to provide needle roller bearing protection during storage. It is therefore necessary to completely lubricate each bearing assembly. It is also necessary to fully lubricate the universal joint kit after it is installed in the vehicle.

Align the yoke in an arbor press with the bearing assembly resting on the base of the press.

Cover the yoke ear with a metal plate that has 0.25 inch minimum thickness. Push the yoke onto the bearing cup assembly.

Turn the yoke over 180° and place a push rod that is smaller than the diameter of the bearing cup assembly onto the bearing cup assembly and continue pressing the bearing cup into the yoke cross hole until far enough to install a snap ring.

Flip yoke over 180*, place second bearing cup over the trunnion and align it to the yoke cross hole. Align the yoke in an arbor press with the previously installed bearing assembly resting on a support on the base of the press.

Place a push rod that is smaller than the diameter of the bearing cup assembly onto the bearing cup assembly and continue pressing the bearing cup into the yoke cross hole until far enough to install a snap ring