M70 TIMING CHAINE TENSIONER, the ball bearing is missing.

[Restor8orman]

I'm looking for a bit of advice regarding the refurb of the timing chain tensioner on the M70 engine of my 1990 E32 750iL. I've stripped it down carefully and am now ready to install a new soft alu crush washer and the O-ring (ref parts #23 and 22 ref. Realoem). My problem is that there was no 5mm ball bearing (#19) present when I disassembled the parts. nor is there any evidence, from the inside surface of the piston, that any ball was ever present. What is the purpose of the ball bearing, I can see it only runs up and down on the inside of the spring. Is it only to prevent the oil from gumming up? Should I buy the #19 ball and install it or just leave things as they were, without it? This my first post on Bimmerforums and any advice from the experts out there is greatly appreciated.

[shogun]

moved to E31 forum

[Mikekugel]

I'm looking for a bit of advice regarding the refurb of the timing chain tensioner on the M70 engine of my 1990 E32 750iL. I've stripped it down carefully and am now ready to install a new soft alu crush washer and the O-ring (ref parts #23 and 22 ref. Realoem). My problem is that there was no 5mm ball bearing (#19) present when I disassembled the parts. nor is there any evidence, from the inside surface of the piston, that any ball was ever present. What is the purpose of the ball bearing, I can see it only runs up and down on the inside of the spring. Is it only to prevent the oil from gumming up? Should I buy the #19 ball and install it or just leave things as they were, without it? This my first post on Bimmerforums and any advice from the experts out there is greatly appreciated.

You don't appear to need the ball bearing. Looking at Realoem and comparing the tensioner individual parts, they all have the same part numbers, and the ball is missing for my 93 M70 850CI. If you remain in doubt, perhaps a chat with a BMW service dept. is in order. There was a reference to BMW SI 110890237? Good luck

[dragon850]

Yeah i was looking for that also, but there is no need

[cartoonz]

I already answered this on the other thread... bearing is passe

[Bimmerboatmd25]

Hey Shogun! Sorry for hijacking thread. New here to the site and still figuring out how to work everything. Would have sent a PM but haven’t figured that out yet lol. Always follow your threads on the 750 thanks for all the great info you put out there! Wanted to buy one of your chip sets. I have a 1991 750il and was wanting a little more lower rpm performance. From all the reading I’ve done your chips work very well. Just replaced spark plugs, fuel filters, o2 sensors, cleaned throttle
Body and maf sensors, power steering pump, Ccv valves, heater core, suspension etc. Figured good time to go ahead and add your chips. I’m also possibly interested in some other things you sell but not sure how I can buy from you or is a list what you have available. I probably should replace ignition wires and rotor distribution caps but haven’t bought the parts yet. Idk if you carry those? As you can see I’ve spent a lot of my own time and money as it is and wallet is getting thin this time of year. You IDE also love to have one of those dimmer switches I saw in a forum somewhere too. I’m here in Dallas Texas in the states zip
Code 75063. Let me know how we do this thanks!!

[shogun]

No problem, I moved it to the right forum. For E32 use the E32 forum in future. As for the M70 chipset, ignition wires etc I will send you a PM, Bosch Motronic you have installed should be for the 1991 E32 750 M70/B50 0 261 200 352 Bosch Motronic M1.7 http://www.pelicanparts.com/BMW/tech...DME-Repair.htm

SI 110890237 (See Service Information SIT 237 08/90) I cannot find the exact text, but the no. is also mentioned in realoem. http://www.realoem.com/bmw/showparts...90&hg=11&fg=25