Fuel Tank Sender Lock Ring

[SteveJ]

I need to remove the lock ring from the 240Z fuel tank, and I thought I would do a search to see if there is a tool to do that. Google sent me down several interesting rabbit holes in this quest. 

I noticed that the lock ring for the older Mustangs looked pretty similar to the one for the 240Z. That ring was cheap, so I ordered one.

It is slightly larger than the 240Z ring. Many older GM cars/trucks have a very similar style and size, too.

The locking ring tools may work, but I didn't feel like ordering one.

Here are a couple I found:

http://blog.virginiaclassicmustang.com/2020/09/gas-tank-sending-unit-lock-ring-tool.html

https://www.ecklers.com/fuel-sending-unit-lock-ring-tool-25-255042-1.html

One of the other rabbit holes I explored was the Honda/Acura lock ring from the 90s. Once I found the Ford lock ring was too large, I thought that the Honda one might be closer due to metric system stuff.

I found the Dorman 579-015 on Amazon: https://www.amazon.com/dp/B002D3Y30U. At that price, I figured it was worth a look.

A new Z lock ring from ZCarDepot is on the left. The Honda lock ring seems to have the same inner and outer diameters as the Z lock ring. It only has 3 inner tabs as opposed to the 4 on the Z lock ring.

I plan on trying the lock ring on an old tank in the near future to verify fit. Given that the 240Z lock rings are cheaper, there isn't a need to switch, but we never know when supply will dry up.

As for a lock ring tool, I decided to make one myself. 

A friend who has worked on a lot more Z cars than I have told me he made a similar one.

[zKars]

Flat blade screw driver and hammer has always worked for me. Tap one tab, then next, it comes off. 

I did make a tool to help, which it does, especially when the tank is still in the car. Based on a short 2” steel pipe nipple that I welded little tabs on that hit on those four little tabs. Then added a bar and 17mm nut welded in the center to put a socket or wrench on. Great if you have a welder.

Interesting that the Honda ring is so similar. Good find.

[dmorales-bello]

I described a tool I made especially for that task using pvc tubing. I couldn't come up with the link in my search but perhaps one of the guys here remembers it.

Sent from my SM-N986U using Tapatalk

[SteveJ]

35 minutes ago, zKars said:

Flat blade screw driver and hammer has always worked for me. Tap one tab, then next, it comes off. 

I did make a tool to help, which it does, especially when the tank is still in the car. Based on a short 2” steel pipe nipple that I welded little tabs on that hit on those four little tabs. Then added a bar and 17mm nut welded in the center to put a socket or wrench on. Great if you have a welder.

Interesting that the Honda ring is so similar. Good find.

I like that idea. It's easy to find the 2 inch pipe and caps in iron around here.  I didn't want to use the screwdriver and hammer because the tank is in the car and half full of gas. I have an aversion to mixing sparks and gasoline vapors.

36 minutes ago, dmorales-bello said:

I described a tool I made especially for that task using pvc tubing. I couldn't come up with the link in my search but perhaps one of the guys here remembers it.

Sent from my SM-N986U using Tapatalk
 

I found it. I like that idea, too.

 

[Diseazd]

20 hours ago, zKars said:

Flat blade screw driver and hammer has always worked for me. Tap one tab, then next, it comes off. 

I did make a tool to help, which it does, especially when the tank is still in the car. Based on a short 2” steel pipe nipple that I welded little tabs on that hit on those four little tabs. Then added a bar and 17mm nut welded in the center to put a socket or wrench on. Great if you have a welder.

Interesting that the Honda ring is so similar. Good find.

I agree. Very simple and works! If you don’t want sparks, you can use a hard plastic material or wood dowel…..doesn’t take many pops with a hammer to “git her done!”

Edited December 25, 2021 by Diseazd

[SteveJ]

Here's the follow-up.

I made a tool like @dmorales-bello did out of a Schedule 40 threaded cap. The downside is that it didn't fit with the tank strap in place. The good news is that the angle iron tool I made worked very well.

It looks like I pinched the o-ring on the sender when I installed it. I used a new o-ring, and I haven't seen a leak.

I tried the Dorman lock ring on my old tank. It had to rotate to the bump to have enough pressure to stop moving. 

I definitely prefer the Nissan lock rings, but it's good to know of alternatives should the good ones dry up.

[zKars]

Here is my tool, just for completeness and give others ideas.