HarleyTechTalk

Technical Forums => Twin Cam => Topic started by: byf41 on July 04, 2020, 12:25:38 PM

Title: TC88 Oil Leak
Post by: byf41 on July 04, 2020, 12:25:38 PM
Ive had this annoying oil leak on my 2003 FXDL since I bought It new . Its not terrible but Is getting worse now so thought I would Inquire about It . Its extremely difficult to determine the source . The oil collects on the bottom of the engine case and around the area between the engine/trans and drips on my kick stand . It appears to be leaking from the area between the engine and trans or possibly from between the engine case halves . That area Is very difficult to access or even see on my bike . I borrowed a flexible scope and looked around best I could . Not coming from the primary or shift seal area . Not sure If Its the engine or trans as I run Syn3 In all . Has anyone had a leak on a TC88 In this area ? If I added dye would It be better to put It In the engine or trans ? Is there a passage running between both In that area as In this picture on 2003 TC88 ? This Is not my bike but this area I circled Is where It seems to be coming from . Looks like a major job regualdless so Id like to be certain before tearing Into It . Appreciate any Input guys  [attach=0,msg1353578]
Title: Re: TC88 Oil Leak
Post by: autoworker on July 04, 2020, 02:20:06 PM
That picture is NOT the same set up as you're 2003.
Title: Re: TC88 Oil Leak
Post by: Scotty on July 04, 2020, 02:27:54 PM
Quote from: autoworker on July 04, 2020, 02:20:06 PM
That picture is NOT the same set up as you're 2003.

:agree:

Your showing a photo of a 07 up Dyna and talking about a 03 Dyna.
Very confusing as a lot of people will look at the photo and say put a new gasket in when your bike does not have a gasket.
Title: Re: TC88 Oil Leak
Post by: Ohio HD on July 04, 2020, 02:34:30 PM
Check the fasteners on the oil pan. Also possibly the gasket was never installed correctly. Or even a slightly cracked oil pan.
Title: Re: TC88 Oil Leak
Post by: chipthedonkey on July 04, 2020, 08:09:15 PM
On your 2003 there are no open oil passages between the engine and transmission cases as shown in the newer model picture.  So there's no oil to leak from between the two.  At least not unless some other major porosity or other issue is allowing oil to escape one casting or the other (not likely).
Title: Re: TC88 Oil Leak
Post by: xlfan on July 05, 2020, 01:25:05 AM
Why not try red primary oil and smelly transmission oil?

The best procedure would probably be tracer dye and UV-light.
Title: Re: TC88 Oil Leak
Post by: rigidthumper on July 05, 2020, 05:47:41 AM
Fastest way I've found is clean everything spotless, and spray the suspect area with a can of foot powder ( yes, like Desinex), and go for a brief ride, then inspect. If it hasn't revealed itself yet, ride a little more, and look again.  This stuff clings to the surfaces, leaves a thin off white coat, that will make the source of the leak easier to spot. Water will wash it off when done.
Title: Re: TC88 Oil Leak
Post by: chipthedonkey on July 05, 2020, 06:39:34 AM
Quote from: rigidthumper on July 05, 2020, 05:47:41 AM
Fastest way I've found is clean everything spotless, and spray the suspect area with a can of foot powder ( yes, like Desinex), and go for a brief ride, then inspect. If it hasn't revealed itself yet, ride a little more, and look again.  This stuff clings to the surfaces, leaves a thin off white coat, that will make the source of the leak easier to spot. Water will wash it off when done.


That is f'ing brilliant.  Who says an old dumass can't learn new tricks?  Thank you.
Title: Re: TC88 Oil Leak
Post by: autoworker on July 05, 2020, 07:34:06 AM
I would be looking at the fittings and hoses between the engine and transmission case behind the cover near the oil fill spout.
Title: Re: TC88 Oil Leak
Post by: byf41 on July 05, 2020, 11:11:07 AM
Yes I realize the picture Is of a different bike/trans , I posted It cause It was the best picture I could find to Illustrate the area In question , sorry for the confusion . The problem Is , when I clean that area good and go for a ride , that area along the mating joint gets a "wet" look to It but not a drip In a specific area , seems to be all along that joint between the engine and trans . Then when you put It on the kick stand It naturally migrates to the left side forming a drip . It will then migrate to the bottom of the engine case , but seems to originate In that area between the engine/trans , above and In front of the pan . To be honest I wasn't sure If my 03 had a passage between the 2 so that eliminates one possibility .
Title: Re: TC88 Oil Leak
Post by: chipthedonkey on July 05, 2020, 12:24:40 PM
Quote from: byf41 on July 05, 2020, 11:11:07 AM
Yes I realize the picture Is of a different bike/trans , I posted It cause It was the best picture I could find to Illustrate the area In question , sorry for the confusion . The problem Is , when I clean that area good and go for a ride , that area along the mating joint gets a "wet" look to It but not a drip In a specific area , seems to be all along that joint between the engine and trans . Then when you put It on the kick stand It naturally migrates to the left side forming a drip . It will then migrate to the bottom of the engine case , but seems to originate In that area between the engine/trans , above and In front of the pan . To be honest I wasn't sure If my 03 had a passage between the 2 so that eliminates one possibility .

What is often mistaken for a leak at the seam or interface between the engine and transmission is common.  Have read/heard/sang of many excuses.  A place for oil vapor to catch, an extra spot to claim satisfaction for cleaning well and regularly, or many others.  But if it's just a dark spot running along the interface where the cases meet you probably don't have a problem.
Title: Re: TC88 Oil Leak
Post by: byf41 on July 05, 2020, 03:01:25 PM
Removed the cover over the oil lines as suggested , dry as a bone In there . Torqued the pan bolts just for fun but Im reasonably sure Its leaking ahead of the pan , bolts were tight . Its not just residue but will drip on the floor/kick stand after maybe 40-50 miles , after wiping It down good . What makes It difficult Is theres a double brace going across the frame In that exact spot . Impossible to spray powder In there as also suggested . It almost looks like It may be coming from that small 2" opening on the bottom of the engine case just forward of the trans . I was thinking about stuffing a small rag In there to plug It off temporarily just to see If that's where Its coming from but Im concerned It might catch fire ? Really appreciate any and all comments .
Title: Re: TC88 Oil Leak
Post by: smoserx1 on July 06, 2020, 04:12:21 AM
I doubt a rag would catch fire there.
Title: Re: TC88 Oil Leak
Post by: hogmandon on July 07, 2020, 08:24:15 AM
I had a similar leak yrs ago 06 RG. Drove me nuts, turned out to be o ring in neutral switch. Don't know if your bike has the same set up.
Title: Re: TC88 Oil Leak
Post by: CndUltra88 on July 08, 2020, 08:12:58 AM
I would put the uv dye in it one hole at a time.
Drain the hole during interval changes ...
Or use a colored oil such a Bel-ray or red-line for the primary or transmission to speed up the search.
Spray the heck outta the area with carb clearner with an extended nozzle to get into all those lil nooks and crannies before you do the dye test.
Its been eating at you since 07 so whats another season of searching for the leak.
Rob
Title: Re: TC88 Oil Leak
Post by: FSG on July 08, 2020, 02:36:58 PM
Quote from: rigidthumper on July 05, 2020, 05:47:41 AM
Fastest way I've found is clean everything spotless, and spray the suspect area with a can of foot powder ( yes, like Desinex), and go for a brief ride, then inspect. If it hasn't revealed itself yet, ride a little more, and look again.  This stuff clings to the surfaces, leaves a thin off white coat, that will make the source of the leak easier to spot. Water will wash it off when done.

Physics in year 11,  16 or 17 yrs of age, we used Talcum Powder on the water surface of a bucket to measure the size of a molecule of clavus oil