OFA O-rings?? Renix

I had to remove my oil filter adapter to slide out the thru bolt to replace the motor mount. Although I didn't know if that was necessary, but it was easy enough. I have a hex head on my Renix OFA and it wasn't siezed or really hard to remove at all. So, I figured, might as well change the o-rings since I had it off. I can see plainly where the o-rings should go BUT, there aren't any o-rings in the "grooves". There is what appears to be o-rings, but they're not rubber, they look like steel/metal "inserts" where the rubber should be. What's up? What am I missing? 88 4.0L

It wasn't leaking at all. The block all around it is dry as a bone. I poked at the things with a dental pick, a screwdriver and they are hard as stone. When I hit them with the pick, they go "tink, tink, tink" (sorry if I'm being overly technical) They're not bouncy or squishy, they feel like steel. Could they just be so old that they've "morphed" into being that hard??

some of the early ones used lead/alloy crush washers instead of rubber o-rings. the fel-pro number for the oring that goes in that groove is 70301, if your metal ring is flattened out I would pick up the oring and replace it with the rubber one. it should be less than 2 bucks at any parts store.

UPON further investigation:

I was able to get the big ring out of the housing. It resembles a very hard brittle plastic like subtance (a.k.a.old compressed oily rubber).

I had never heard of the crush seal idea, must be on older, older models.
All I've ever heard about MJ's XJ's etal. is the 3 rubber rings. So, rubber it is. I'm beginning to understand that all the "oddball" stuff I'm running into is actually ME !!

I've never actually seen one of the crush rings personally but i've heard of their existence

that part number I posted is for the larger o-ring that seals the adapter, it should take one on each side. not sure on the o-ring for the bolt itself I don't show a part number for the kit on that year but I'm sure someone will chime in soon enough with a part number for you.

ParadiseXJ said:

I had to remove my oil filter adapter to slide out the thru bolt to replace the motor mount. Although I didn't know if that was necessary, but it was easy enough. I have a hex head on my Renix OFA and it wasn't siezed or really hard to remove at all. So, I figured, might as well change the o-rings since I had it off. I can see plainly where the o-rings should go BUT, there aren't any o-rings in the "grooves". There is what appears to be o-rings, but they're not rubber, they look like steel/metal "inserts" where the rubber should be. What's up? What am I missing? 88 4.0L

It wasn't leaking at all. The block all around it is dry as a bone. I poked at the things with a dental pick, a screwdriver and they are hard as stone. When I hit them with the pick, they go "tink, tink, tink" (sorry if I'm being overly technical) They're not bouncy or squishy, they feel like steel. Could they just be so old that they've "morphed" into being that hard??

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Crush washers are a possibility. Also, those o-rings do harden considerably with age - some of the ones I chipped out (literally!) came out in small sections, but were originally some elastomer - probably Viton, EPDM wouldn't last as long.

The hex head should be 5/8", and I do not suggest using impact on it! Recall that what looks like a large screw has a hole drilled down its axis for about 3/4 of its length, and it's cross-drilled up top (and the whole damned thing is probably made using powder metallurgy, instead of wrought material!)

I've done this job a few times, so let me pass along a few things I've found to be helpful:
- Make sure the threads in the block and on the screw are clean. Use a wire wheel on the screw, use a pick in the block.
- Similarly, make sure all of the o-ring grooves & seats are clean. A wire wheel won't go amiss here, just be careful to not gouge the thing!
- A light coating of RTV black in the o-ring grooves and on the o-ring proper won't go amiss - on all of them.
- PTFE paste should be used on the screw threads. PTFE paste may also be used in place of RTV on the O-rings.
- The FSM sez that screw gets 75 lb-ft of torque - I think that's excessive. I'll go with 35-40, run the engine for a few minutes, and check for leaks. I've done this job a couple dozen times, I've only had to "nip up" the screw once.

Removing the hex vs. the torx is extremely easier. Better grip, and some working space I got it off with a 3/8 size breaker on first try. When I first saw it I thought ?metal?, but after I pried the big ring out it did crumble into a couple pieces and then I realized it was just 25 yr. old rubber.

Does 88 hex head specify the 75 lb. or the later torx, or both? It certainly wasn't on there with 75 fp. Thanks for the tech tips.

Morris 4x4 Renix 33002970K $3.99

ParadiseXJ said:

Removing the hex vs. the torx is extremely easier. Better grip, and some working space I got it off with a 3/8 size breaker on first try. When I first saw it I thought ?metal?, but after I pried the big ring out it did crumble into a couple pieces and then I realized it was just 25 yr. old rubber.

Does 88 hex head specify the 75 lb. or the later torx, or both? It certainly wasn't on there with 75 fp. Thanks for the tech tips.

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I'm pretty sure that was RENIX FSM value - all I know is that it just seemed FAR too high - and when I tried to use it the first time, I snapped the damned screw off.

Fortunately, I had another handy...

Well, I called the dealer today. They told me the o-rings were listed and priced separately...at $5.50 EACH. I wasn't about to pay $16.50 for 3 o-rings. Especially since they not made of some "special" space age material. So the cheapskate in me went to the local speed shop where they have an huge array of all types of o-rings.

The gentleman fit me up with three properly sized o-rings for .30 each...that's 90 cents. Buna-N (Nitrile) o-rings. Boo-ya.

ParadiseXJ said:

Well, I called the dealer today. They told me the o-rings were listed and priced separately...at $5.50 EACH. I wasn't about to pay $16.50 for 3 o-rings. Especially since they not made of some "special" space age material. So the cheapskate in me went to the local speed shop where they have an huge array of all types of o-rings.

The gentleman fit me up with three properly sized o-rings for .30 each...that's 90 cents. Buna-N (Nitrile) o-rings. Boo-ya.

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Cheap bastard.

It seems SOME people have good luck at the dealer, myself not included. I hit two dealerships to get "all three", wasting half a day to figure out later one was the wrong size. Did I check it to the neck? No, I thought that was why dealerships had parts departments.


Long story short, x2 on the morris4x4 link old man posted, sure shipping is more than the o rings, that's why you buy two or three extra sets.... I'm in this for the long run.

xcm said:

that's why you buy two or three extra sets....

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I'm not about to shell out another 90 cents "just in case" :wow:

xcm said:

It seems SOME people have good luck at the dealer, myself not included. I hit two dealerships to get "all three", wasting half a day to figure out later one was the wrong size. Did I check it to the neck? No, I thought that was why dealerships had parts departments.


Long story short, x2 on the morris4x4 link old man posted, sure shipping is more than the o rings, that's why you buy two or three extra sets.... I'm in this for the long run.

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I've bought o-rings at my local dealer twice, first asking for o-rings for a '91, then later asking for ones for an '87 (I have a '91 with the HO engine, but it has a vertically-mounted OFA with a hex head, like a Renix XJ)... both sets they sold me were the exact same thing, and do not fit well. $32 later My OFA is still leaky. :doh:

Might give those those o-rings from Morris4x4 a try and see if I have better luck...

Red91Laredo said:

I've bought o-rings at my local dealer twice, first asking for o-rings for a '91, then later asking for ones for an '87 (I have a '91 with the HO engine, but it has a vertically-mounted OFA with a hex head, like a Renix XJ)... both sets they sold me were the exact same thing, and do not fit well. $32 later My OFA is still leaky. :doh:

Might give those those o-rings from Morris4x4 a try and see if I have better luck...

Click to expand...

4720363 for 07/17/92-1998

33002970K for 1987-07/16/92