[mrrogers78]

I recently purchased a used Rubicon and it makes a disturbing sound at very low speed just as transmission is about to disengage. I found evidence that it may have been swamped but have since thoroughly cleaned radiator, oil cooler and changed the oil. My question is, is the noise I am hearing an indication of serious damage or is it normal? I'm new to this so my apologies if I am going against protocol. I am hoping someone with experience servicing these machines will be able to help. I'm attaching a video with audio to show what it is doing. For background the machine is basically in mint condition and only has 7xx miles. The machine is fully warmed up and in drive with D1 selected. Listen closely when you see speedometer read 4 mph. File is too big to upload so I will add a link to the video on YouTube. Thanks.

 

[Hondafaith500]

I'm no mechanic, but from my own previous experience swamping my own Rubicon and seeking advice here, the Hondamatics are very sensitive to any kind of contamination....especially after being swamped. I did 3 oil changes as per instructions from the dealership after swamping mine. Got **** lucky apparently cause its still running good. Hopefully it has not been swamped, what have you found for evidence of this so far?

 

[mrrogers78]

Just mud under the plastic and dried mud packed in radiator and oil cooler. Some debris in bottom of airbox. This doesn't necessarily mean it took water/ mud into the intake or exhaust but maybe was stuck bad and worked hard. It may have been ran hot as well if the oil cooler and radiator were not getting good air flow.

 

[mrrogers78]

First oil change when I got it, the oil was pretty dirty. After I cleaned the radiator and oil cooler (externally), I changed the oil again in case it got too hot and the oil was perfect when it came out....light Amber.

 

[Forman500Rubicon]

Do another oil & filter change and put in a top quality synthetic ATV/UTV oil that is wet clutch compatible.

 

[mrrogers78]

I used this stuff. Not synthetic but is JASO and MA rated.

 

[4 HONDA FORMANS]

I would recommend running honda oil. I dont think that will solve your problem though. Its possible to have somthing going on with the timing chain. Thats where i would start

 

[toodeep]

Your oil pressure is low and because of that the transmission is on it's way out. It might last a day, could last for years.

 

[mrrogers78]

Is oil pressure low because of pump volume or tolerances too high in passages? Would replacing the oil pump do any good? Keep in mind that it only has 700 miles it. I am considering getting a new Foreman with the foot shift but I may be able to keep this and use until transmission fails. Sounds like a replacement trans is $1,200.... What would you do if you were in my shoes?

 

[mrrogers78]

The dealer I bought it from only sells used ATVs and snowmobiles. They get their stock from dealers that take trade-ins. My guess is that the owner traded it in when they heard the noise. Probably got $2,500 on trade and the dealer I bought from probably paid a little more or same and sold it to me for $3,500. Now it's my problem and I don't want to screw someone else over with it because it that wouldn't be right. I am afraid if I traded it in it would just get passed on in it's current condition... pretty crappy deal all the way around ☹

 

[toodeep]

It's a no win situation for everyone. I would see if the company you bought it from could get the parts for cost from the dealer they bought it from (oil pump, transmission, gasket kits and a set of rings). Set them parts on the shelf and ride it until it goes out completely. Or have them sell it again and the problem goes back to them.

 

[spackman4wheel]

mrrogers78, I'm curious what you decided to do. I unfortunately recently purchased a 2004 Rubicon making the same noise at low speed and when initially going down hill. Trying to decide if I put money into it or get out from under it. Luckily I got a decent deal on it, but now I am finding out why. Curious what you ended up doing or are just going to ride as is. Thanks

 

[brianb1263]

I work on exclusively Honda Rubicons. What your describing sounds like an old style 01-04 oil pump with a stuck pressure relief valve. When cold it works. Then once the oil warms and thins there is not enough pressure at low RPM’s. You get a little chatter on take off and more chatter if the engine is braking and the engine speed is close to idle. Replace oil pump. The replacement pump has a new pressure relief system that is bulletproof. You can verify this with a oil pressure check.

 

[brianb1263]

Normally this does not cause damage to the Hondamatic. I have replaced just the pumps on several 04’s. News flash. The 2004 Rubicon’s have the updated Hondamatic’s. So the 04 is specifically worth the oil pump replacement.

 

[mrrogers78]

Brian is the guy that actually replaced my oil pump. Works perfect now. Thanks Brian!

 

[mrrogers78]

mrrogers78, I'm curious what you decided to do. I unfortunately recently purchased a 2004 Rubicon making the same noise at low speed and when initially going down hill. Trying to decide if I put money into it or get out from under it. Luckily I got a decent deal on it, but now I am finding out why. Curious what you ended up doing or are just going to ride as is. Thanks

I already posted below Brian's comment but in case you don't get a notification he is spot on. He replaced my oil pump and the machine is as good as new. Your Hondamatic is most likely fine.

 

[spackman4wheel]

Thank you both for your reply. I'm definitely going to check the oil pressure and take your advice on the oil pump. It's a lot better of a situation than I was thinking, but I assume replacing the oil pump will be pretty labor intensive. Any idea on what I should be expecting to pay a local shop to replace the pump? Not sure where you are located Brian, but sounds like your the guy I would want to tackle this. Thanks again

 

[Tim-ANC]

@brianb1263 can I trouble to you to comment on my problem: 2001 TRX500FA chattering noise from transmission area

I would really appreciate your opinion.