NP205 Leak at Speedo connection - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**PDXk5** · 03-16-2020, 02:27 AM

So, after research on the Forum, I identified I needed to replace the seal for the drive gear to remedy a leak I had at this spot. I purchased two seals from Motor City K5 and installed them during our office closure at Christmas. Problem solved I thought.
Today I noticed a small drip under the rig today and after inspection found oil beaded up on the speedometer ratio adapter.
WTH ! I haven’t moved the rig since installing the new seals. Clearly, the seals aren’t working. What causes the gear oil to seep up into the ratio adapter if the truck isn’t being driven?
The seals seam to fit snug into the threaded coupling and the drive gear didn’t appear to have noticeable grooves worn on it.

Any suggestions on what I should do to eliminate this annoying leak?

**Mts67C10K20** · 03-16-2020, 12:16 PM

Since it has not been driven to circulate any fluid
Could it be that the adaptor or possibly the cable
are full of fluid and draining back?
Curious to see what comes up

**PDXk5** · 03-16-2020, 10:04 PM

Thanks MTS,
I hadn’t thought of that. That may very well be what’s going on. Maybe I’ll disconnect and let it free drain into a pan for 24 hours before reconnecting.

Andy4639 · 03-17-2020, 07:59 AM

Try some o-ring grease to stop it also maybe on the housing and threads.

03-16-2020, 02:27 AM	#1
PDXk5 Senior Member Join Date: Aug 2012 Location: Portland, OR Posts: 920	NP205 Leak at Speedo connection So, after research on the Forum, I identified I needed to replace the seal for the drive gear to remedy a leak I had at this spot. I purchased two seals from Motor City K5 and installed them during our office closure at Christmas. Problem solved I thought. Today I noticed a small drip under the rig today and after inspection found oil beaded up on the speedometer ratio adapter. WTH ! I haven’t moved the rig since installing the new seals. Clearly, the seals aren’t working. What causes the gear oil to seep up into the ratio adapter if the truck isn’t being driven? The seals seam to fit snug into the threaded coupling and the drive gear didn’t appear to have noticeable grooves worn on it. Any suggestions on what I should do to eliminate this annoying leak? Attached Images

03-16-2020, 12:16 PM	#2
Mts67C10K20 Senior Member Join Date: May 2017 Location: Dowagiac Michigan Posts: 202	Re: NP205 Leak at Speedo connection Since it has not been driven to circulate any fluid Could it be that the adaptor or possibly the cable are full of fluid and draining back? Curious to see what comes up

03-16-2020, 10:04 PM	#3
PDXk5 Senior Member Join Date: Aug 2012 Location: Portland, OR Posts: 920	Re: NP205 Leak at Speedo connection Thanks MTS, I hadn’t thought of that. That may very well be what’s going on. Maybe I’ll disconnect and let it free drain into a pan for 24 hours before reconnecting.

03-17-2020, 07:59 AM	#4
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: NP205 Leak at Speedo connection Try some o-ring grease to stop it also maybe on the housing and threads. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.



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