There is only one belt besides the timing belt in 850, S70, V70, C70 and XC70 models up to/including model year 2000, and it’s called the serpentine belt, accessory belt or auxiliary drive belt, depending on who you ask. It transmits power from the crankshaft of the engine to the alternator, steering pump and air conditioning compressor.
Check your owners’ manual for the change interval (at what mileage you need to replace your serpentine belt). If you have your Volvo serviced regularly at a Volvo dealer or independent Volvo repair shop, it’s probably on their radar, and you probably don’t have to ask them to perform this. If they’re good, you’ll know if this belt has been changed recently or if it will be soon because they will have discussed this with you.
Serpentine Belt Parts
First off, the belt for the 850 T5 is Continental part #6PK-1743 (visit our sponsors to find your model #). Here’s some points to keep in mind:
- There’s two lengths for the 850. Be aware of this when you order; the tech will need your model and year, and maybe even your serial/VIN number.
- Volvo-branded belts are made by Continental. If the Continental is cheaper than the Volvo belt, buy it.
- If you take long trips, keep your old one in the car… you know if this belt ever breaks, you’ll be in Mexico or somewhere where a replacement will take 3 weeks to get to you by mule (not necessarily a bad thing).
Serpentine Belt Tools
There’s two difficult things to this operation: operating the tensioner, and routing the belt. The tensioner is hard because you need a special tool, or you need to make one, to relax the tensioner to get the old belt off, and the new one on. The second difficulty is routing the new belt on the pulleys. IPD makes a serpentine accessory belt tool set that may be worth the US$30 to you. I built my own with a vise grip tool and three US quarters. For a belt guide I used a coat hanger.
Serpentine Belt Procedure
Here’s a brief rundown on how to replace your serpentine belt, along with some tips to make the job easier.
- Make sure you have light. Sunlight, flashlight, overhead electric lights, whatever. It’s dark and narrow in that belt area; work this out before you start.
- Take a few pictures with your phone before you even start (it won’t be an Ansel Adams, trust me, but it can save you hours of headache if you forget the belt routing) of how the belt’s routed first. View these when you’re putting the new belt on.
- Put the business end of the tool in the tensioner. Pull toward the front of the car. With your other hand (or if you’re lucky, ask your helper) unloop the belt from the top-most pulley. Release pressure on the tensioner and remove your tool. The belt should then come off the rest of the pulleys with ease.
- Once the old belt is off, compare the old and new belts to make sure you bought the right one.
- To get the new one on, start with the lower, rear-most pulley and worked up from there. Use those photos you took earlier!
- To complete installation of the new belt, do the tensioner thing again and loop the belt around the top pulley. Mine was a bit difficult even with the tensioner at full-forward. It took me three tries. When it’s on, double check and triple check that the routing is correct.
Check out the full forum post for more detailed information as well as pictures of the entire process!