MVS Volvo Forums member Hobbs got a quote for almost $2500 to fix his XC90’s READ assembly. MVS Forums Contributor and all-around Volvo ninja jimmy57 explains what the READ assembly is, why it’s important, and what it does in XC90s.
Rear Engine Ancillary Drive, READ, is the gearbox on side of engine that links crankshaft to the camshaft drive chain and drives the alternator and the serpentine belt that runs a/c compressor, water pump, and power steering pump.
The bearing will get worse and the metal coming from failing bearing can be damaging to the engine.
XC90 READ Assembly… So Why?
jimmy57 »
Comment on READ unit and why it is there. There was a time when to play in the league Volvo wanted to play in you had to meet the buyer’s wants for a 6 cylinder engine. The problem was the existing 6 was too long and the problem of large turning circle could only be fixed by giving more degrees of wheel turn. You can only get more wheel turn with wider track requiring wider bodywork or narrower engine allowing frame to be more narrow. The READ unit takes belt and cam drive away from end of crankshaft and allows the engine to be no longer than the shorter version of the Volvo 5 cylinder. The crank stops at the front main bearing, there is no damper or anything past that bearing.
Read solution is not the craziest thing a car maker has done. If you google Audi v6 and v8 engines you will find their timing chains, oil pump chain, and for some versions a accessory shaft drive chain. Some of the chains run in a guide set that forms a C shape and the chain never has a straight run. Oh and the chains are on the transmission end of engine. The bill for chain, tensioner, and guides is easily double that of READ overhaul.
XC90 “Reed Assembly” … $2,450 to fix?
Subscribe to the MVS Newsletter
The MVS Volvo Newsletter is a once-a-month email delivered to your email. It’s simple to unsubscribe at any time if you change your mind.
Last Updated on June 4, 2025
