Squeaking leaf springs: causes, repair options

You have a great truck, but it has one little problem: the rear leaf springs squeak. In most trucks, rear leaf springs are made of several "leaves." When a spring flexes, these leaves move against each other. What are the common problems that cause squeaking?

• Sand, small rocks stuck between leaves
• Worn-out spacers (anti-friction pads)
• Leaf spring rubs against one of the rebound clips
• Squeaky leaf spring bushings

In many cases, squeaking starts after driving on unpaved or muddy roads, as small rocks can get stuck between the leaves. If you check 4x4 forums, many truck owners advise pressure washing the leaf springs after mudding or driving on unpaved roads. Do car manufacturers recommend cleaning leaf springs? Some car makers don't mention it, but some do. For example, the owner's manual for the 2013 Ford Super Duty says:

Rear suspension components may require regular cleaning with a power washer or a thorough rinse with a strong stream of water if the vehicle is operated in dusty or muddy environments.

We also found the GM service bulletin 06-03-09-004M for the 1999-2007 Chevrolet Silverado and a number of other trucks about a squeaking noise from the rear of the vehicle. Here is the link to the bulletin on the NHTSA website. The bulletin recommends pressure-washing the leaf springs to clean the dirt first, then drying the springs with compressed air and then greasing the inserts (spacers) with a special lubricant. Judging by the part number of the lubricant provided in the bulletin, it's the Molykote ™ M77 paste. However, the bulletin warns that it's a temporary measure and periodic cleaning and re-applying grease may be necessary throughout the life of the vehicle. Many truck enthusiasts recommend not to use any grease on leaf springs, but in this case, we will take the manufacturer's (GM) recommendations. We also found the service bulletin NTB18-003 for the 2004-2015 Nissan Titan. The bulletin instructs cleaning the working surface of the rear leaf spring tip inserts (spacers) to solve the noise concerns.
It's worth noting that the fact that there is a service bulletin doesn't mean that the problem is covered under warranty.

Another common problem that often causes squeaking is when the inter-leaf spacers wear out allowing metal to metal contact between the leaves, see the photo. If a spacer is worn out or missing, the lower leaf grinds into the leaf above. For that reason, it's a good idea to replace inter-leaf spacers if they look worn out; parts are not very expensive ($15-$30 for a kit). For example, the Toyota service bulletin T-SB-0273-17 for the 2016-2017 Toyota Tacoma recommends cleaning and removing grease and dirt between the leaf springs and replacing silencer pads (spacers). Here is the link to the bulletin. The bulletin, though, warns against using any grease on the pad and spring surface. The bulletin also provides instructions for mechanics on how to find the source of the noise. One more possible source of squeaking noise is the contact area between the leaf spring and the inner edges of the rebound (wind-up) clip; marked in the photo. For example, the Nissan service bulletin RA05-003 for the 2005-2006 Nissan Frontier instructs mechanics to inspect the inside of the rear leaf spring wind-up clip plastic cover for contact (rubbing) with the leaf spring. If there are signs of rubbing, the bulletin advises applying grease (Molykote 7 ™) between the leaf spring and wind-up clip plastic cover. For a similar concern, the bulletin RA05-002a for the 2004-2006 Nissan Titan advises replacing the leaf spring wind-up clip cover if signs of rubbing are present.

Worn leaf spring bushings as well as shackle bushings are known to cause squeaking noises too. Parts are not expensive, but replacing leaf spring bushings involves a considerable amount of labor. In most cases, the leaf springs will need to be removed, although some mechanics can do the job with leaf springs in place. In many trucks new bushings will need to be pressed in. There are plenty of YouTube videos on how to do it.