I have a wierd noise coming from the drivetrain of my 091 bus tranny. Best I can describe it is a rapid drum beat. Not too loud but loud enough to scare me. My first sand car, so all of these noises are new to me. Kind of sounds like a bolt tapping the block that backed out of a torque converter on an automatic. Rat tat tat in rapid sucsession. The car drives fine, shifts fine, no missing teeth... Hoping it is something simple like a CV. Do not really know what a bad CV sounds like either! Pulled the boots off , no metal shavings, no play...I dont freak'n have a clue! Any ideas, or methods of elimination? Thanks

about all i can say is, if your tranny has weddle gears, they are supposed to be famous for being noisy until they are well broken in.

check your rear brakes. problems with bolts hitting or rubbing is very common

We just went through this. I have an 091. Last season it started clicking. A small noise at first that sounded like someone was clicking a ball point pen open and shut. It soon got louder and sounded like what you describe, a bolt or something hitting metal. The noise was only under load. It quit as soon as the throttle was released. It the frequency of the clicks kept pace with the RPM. Going faster meant more clicks

The good news: we now have 4 extra CVs to replace the 8 year old ones should they really go bad.
The other good news: We now have a brand new weddle ring and pinion.

When we finally pulled the transmission and then the bell housing there were 2.5 teeth from the pinion gear lying in the bottom of the case.

More good news: Rancho gusseted the new case we got. The old one was not gusseted. We got a better breather to keep the trans from puking out the nose cone breather. This trans is painted a nice black. We got some new bearings and other stuff.

Bad news: Those new R&Ps aren't cheap. It was about $1000 in parts and a little more than half that for labor.


I'll cross my fingers for ya that you have a CV issue or a really tight transmission.

Good luck

I had bad stub bearings which made the rear break bolts rub and make this sound.

Have you checked the throwout bearing?

Maybe the axle is too long and tapping the CV cup????

We need more information:

Is the noise consistant, or does it come and go?

Does the noise happen only during acceleration?

Does the noise continue during decelleration?

Do you notice the notice getting better or worse as the suspension goes up and down, or is the intensity unrelated to suspension position?

Does the noise keep time with wheel revolution, or engine RPM?

Does the noise occur when you coast out of gear?

Some tips:

CV damage cannot be found simply by removing the boots, you really need to dismantle all the CVs and clean all the grease off to carefully inspect them. This is something you should do every summer anyway.

The axle banging on the CV flanges will not produce a constant clicking or knocking. It will only be intermittant, and it's unlikely it would as loud as you described as "loud enough to scare me".

It sounds like it's either CV's or a ring gear, but it will depend on what your answers are to the above.

Had a similar problem a few years back ended up one of the bolts on the rotor was backing out and would hit the trailing arm everytime it came around. another possibility?

Ahhhh, I am going to take it out to Gordons Sat. and go through all of these senarios. It just started making the racket last Sun before we packed it up. Just put in a Morphic Light Bar tonight, looks great. The actuator response is really quick, very impressed. Lots of $, but a high quality product. Anyhow, I hate that I got the light bar in and I can not seem to keep my mind off this ghostly noise! I only have paddles and trailering tires so I cant run it up and down the street very well to test it at home. I did however, jack the car up in run it in 2nd gear for a bit, no noise under light acceleration or idle speeds. I am assuming that it will require a load. I do remember that it does not make any noise while coasting, just cant remember if it was doing it during a downshift deceleration. Thanks for the help, will get back with the answers Sunday. Will post a few pics tonight...

A few pics....

b4 u go out, jack up the rear end and spin each side all the way around by hand. You should be able to hear where the noise is coming from if its your axles or cvs....wheel side or tranny side... also at the same time you will be able to tell if the wheel is binding from the cv locking up or........ it may be a simple fix. If you dont hear the noise, then its probably inside the tranny.

Were do u live, I can lend u some street tires to test it if u wanna come to SD.

Hey, I appreciate that! I just hung up with a buddy and he is going to bring a set in tomorrow. I had my wallet out the other day on the Kartek site and just about bought a set of their new beadlock wheels, but I knew if I did I would take the car to Ocatillo! I am trying my best to keep this thing in the sand! Too big of a puss to put it in the dirt. Oh, I live in Hell Centro.

JDubYa

Cool, by the way, how is the light bar controlled? Do u have a switch? or buttons?

By a pancake toggle, the one in the middle of the two switches at the top of the control panel in the pic. Wanted to put it in the steering wheel, but loosing the removability of the wheel or unpluging it every time made my opt for the dash.

OK, jacked the car up an ran it on jack stands, no noise. Spun the tires around by hand, no CV noise. No bolts loose on the rotors. Ran it up and down the street, no noise! Weird. Need to get it back in the sand I guess.

What do you remember about the noise when it occured? Was it an evenly space knocking that seemed to be in time with tire rotation, or was it a random knocking that changed with the terrain?

If it's a random knocking, I suggest you look at your suspension, such as your rear swing arm pivot bolts, shock bolts, and axle bearings bolts. A loose bolt could be the problem, I've had that happen.

The street isn't duplicating the josseling of the chassis like the irregularites of the dunes provide, hence I suspect suspension if it's a random knocking sound.

Regular intervals, increases with speed. I remembered something tonight that may be something. The tranny was leaking slowly over the summer, so I topped off the case with Lucas leak stop for manual trannys at the advise of someone who had used it in the past. It seemed a bit thinner than 95/145 gear oil but not by much. Could this be the culprit? Oil to thin or something? It does not start making the noise until it is warmed up a bit.

OK then. If it increases with speed, do you remember if the knock changed in frequency with gear change, OR, were gear changes no relevance to the frequency?

If it's only affected by speed (tire rotation), it's very possible it could be CV's or a ring gear. If you haven't inspected your CV's by removing and cleaning all the grease off in the last 2yrs, that's what I would do next, because it needs to be done annually anyway (or every 15 trips). Any shop can tell you if any CV parts need to be replaced if you don't know what to look for. It's possible that with some heat the CV's are catching inside, making a noise with each tire rotation. If you remember the noise increasing with suspension compression or extension this points to CV's even more.

Hey this is good! Narrowing things down some. No, the sound does not change in different gears. I can feel a bit of the knocking in the shifter but very little. Now if it was the ring gear would I feel or hear something while coasting or hand spinning the tires? Can the ring gear sometimes only make this sound under a load? Seems like it would make it regardless if teeth were mising. Truth is I have no idea, but makes sense, I think!

JDubYa

this may sound silly but did you have paddles on the rear? could it have been the paddles coming in contact with the ground as the tire rotated? i've noticed a noise that is from the paddles that i guess could be described as you did. just a thought!

I'd check the CV's thoroughly first just because those are easy to check and replace.

When ours was doing this it would only make noise under front load. WE jacked it up and spun it, no noise. We drove it backwards in straight lines and in circles with someone outside the car walking next to the car, no noise. We drove down wash road to the now removed train tower and it would only make noise while accelerating or using enough gas to maintain peed, no noise on decel.

I refused to believe it was a trans problem. Like you said, " If there's missing teeth it wll make a noise no matter what."

I even loaded my wife, my mom, her sister and her brother in-law up for a trip to China Wall--stupid me. It would have been a tough drag out if it had just let go completely.

There seems to be a lot of things to check first. Save the expensive one for last, just be careful.

Usually, but not always, if the ring gear has a bad spot it will always make a noise with a load...... usually. This may change as the transaxle heats up and cools down. If you feel it through the shifter that points to the transaxle, likely ring gear.

If the noise comes and goes as the car suspension goes up and down, that would point more toward CV's, but it's unlikely you'd feel that through the shifter unless it was really bad.

Again, you should take the CVs apart and inspect them now, unless you've done this in the last year or 15 trips.

If you go to the dunes like you are now....I think there's a high probability you'll be disappointed, and possibly do more damage by waiting for things to break.

The other option is to drain the transaxle and look for metal shavings. If you have a magnetic drain plug you may be able to easily determine if something is wrong with the ring gear. Without a magnetic drain plug, shine a light into the drained oil to find sparkles for metal.

I have pretty much decided we have narrowed it down to the tranny. I really did not want to have to pull the motor, just put it in there! Tis the way it goes. I am going to watch my guy do the tranny repairs, maybe I will have a better idea what goes on in there. Tempted to just slap a 2d in but I am not convinced they are all that much better. I have no idea what the repair will cost, that is if it is just the ring gear. I have been reading about this nose cone business. This lack of knowlegde is driving me nuts. I guess we all have to pick it up as we go. So, this nose cone is where on the tranny? I am assuming it, as the name says front or nose of the tranny. I want to cover all upgrades if I am going to pull the tranny this week. I see things about tranny pumps as well. So, it has Weddle gears and all, but in your opinions what other mods should I have done while I am at it? Rebuild and sell go to the 2d or keep the 091 and do the nose cone and tranny pump and whatever else? Your thoughts? This 091 was built by Transworks and I know thay do good work so some of these things may already be in there. I know one thing for sure that this is coming my way....

What evidence makes you believe the transaxle is the problem, eliminating the CV's as the cause of your noise when you haven't disassembled the CV's yet? In 1hr you can take out the axles and inspect the CV's. You need to take them off anyway to remove the transaxle.

As for the 2D, if you have over 300HP you really need a 2D with a Transwerks HD nosecone kit. That kit uses a Honda wheel bearing that provides much better main shaft support. Another alternative is the Funco nosecone which is a similar fix. The 091 doesn't have a nosecone upgrade because the 8" ring gear usually goes before the main bearing. The 2D has a 10" ring gear, which is the 091 weakness, but be prepared for a $7K bill for a new 2D because Weddle's gear prices went up 20% recently.

Seaduner you have a great point! I am more panicing than anything. I just want to work all of the kinks out before the fisrt weekend in November. Going to the Morpic Regatta that weekend, and would like to run with them without any problems. The reason I dismissed the CV's was from what we all have talked about was they would be making the noise with or without a load. They do not make any noise no matter what I do. Now, to my untrained eye, when I take the CV's out what am I looking for? I am sure there are all kinds of little things, but what are the obvious things a dosent know crap about CV's guy would look for? Besides the metal shavings and broken of pieces obvious. Any one have picks of bad CV's? Are they rebuildable? Sh_t I have not even priced them yet. Dont get me wrong, I have a knowledge of mechanics, but transaxles and CV's are 100% alien to me right now. But, not for long! Thanks for any insight and all of the help to this point.

JDubYa

So I pulled the boots off and I found that the passenger side moves in and out quite a bit more than the drivers side. Passenger side slides about an inch back and forth. The drivers side only about a 1/4 inch or so. The passenger side seems really loose and I say it in shame Seaduner clanky and noisy. I think I have jumped the gun on it being the tranny. So...the thing is I dont know how much side to side travel you should have with the axle. There is very little side to side movement or looseness, like a worn out bearing on either side. They had grease but it looks to be a bit on the dry side. So the next question is do you replace them all at the same time or just the bad one(s). These have been in the car since it was built about a year and a half ago. I would really like to fix this myself for the experence. The videos below are the passenger side in #1 and drivers side in #2. Let me know what you think.

JDubYa



http://www.youtube.com/watch?v=ZBIEwS764BU

http://www.youtube.com/watch?v=qMBYA2-G8wI

Not much side play on the #2 video but if it has been ok for 1.5 years now might not be the issue in whole. You should have about the same travle side to side on both axles. This needs to be checked at both extremes of travel also to ensure not too short or long of an axle. I would definately pull them out to clean and inspect.While removing them carefully note their orientation to be sure you get them togather correctly. You got a 50-50 chance of getting it wrong . Outfront Motorsports (Formerly Outback)has a great writeup on assembly. Look for pitting on the star ( center) and outer. Look for cracked or broken cages. If you are running decent power and travel I would go with the good 300m cages also. Remember again if you do disassemble the cv's they go back togather in a specific way. Get it right or you will be buying new ones really soon. Good luck and wear latex gloves cv grease is some nasty stuff.
p.s. Cat desert gold grease works well as does Swepco and Bel Ray.

OK, I assume both wheels were OFF the ground when you checked the side play, correct?

Before you take off the axles you should take off your shocks and lower the car so the axles are level. This will likely make the flanges at their closest distance from each other, per side. With the axles level, check the side play again and report back what you find. You should have at least 1/4" play. As long as you have 1/4" play at full extension and at shortest distance (level axle) then don't worry about it, it should be fine.

If both axles turn out to be the same length you may have one of these scenarios:
1. The car builder didn't make the chassis to have exactly the same swing arcs on each arm
2. You may have a bent swingarm
3. The transmission may be positioned slightly to one side, either by design or caused by an accident.

Don't panic yet, this may be OK. Once you find out the axle lengths, check level play, and inspect your CV's, you'll be able to figure this out better.

Measure the full extension angle of your axles in relation to the side of your trans when the suspension is at full extension. If your over the limit (I believe 26 degrees is the max recommendation) you may want to reduce that a little.

Make sure you "clock the 2 CV's" with each other when you put them back on each axle. I recently put some information about clocking CV's in the Outfront website describing the process.

As for recognizing damage in a CV, clean them up pristine and make a trip to your local parts house. Those guys can train your eye on what to look for, and what the limit is for wear on each part.

So go ahead and get greasy LOL. And listen to HOTRNHELL, use latex gloves! Oh, and don't accidentally track the grease into the house like I did last month.

Well I think this will pretty much explain the problem, I have some work to do........Damn! Seaduner and everyone else thanks for the help. Where should I buy the gears? Direct form Weddle? Are there any other mods I should do while I have the tranny out? Wife said if I buy a Mendiola my shaft will be getting no input!

JdubYa

Them there looks like gear teeth on dat der magnet.

OK, now you have your evidence, and a plan, that's the good news. You saved yourself a disappointment in the dunes. Time for a rebuild.

Yes, have your trans builder get the good stuff, Weddle gears. Ask if Weddle offers the Klingelnberg Palloid technology on VW ring a pinion yet. That's the best.

So what kind of engine do you have and how much HP? Turbo? Just curious.

I have a 3.5 turbo from Vtec Performance in Oregon, 430 hp. Those were Weddle teeth. I am going to pull out the motor/trans tomorrow night. Hope to have fixed by Nov 1st. Hope my tranny guy can get the parts fast. Pretty sure we can get it done by then. Wondering if I should just buy a whole new tranny and have this one rebuilt for a spare. Do you think the Mendi is that much better? Long run cheaper? I assume switching to a Mendi would require more than just the tranny? Different axle lengths, CV's, mounting setup differnt? I ran this car pretty hard for a year this is the first problem with the drivetrain. The motor is brand new.

JDubYa

Ouch!! thats gonna hurt the wallet. I'm sure Slappy would agree.... Far better to find in the garage than at the bottom of a big bowl in the middle of nowhere on the first run of the long weekend. Get her fixed and back on sand season is upon us. Where you located?? lots of good tranny builders in Cali and AZ.

Getting 1yr out of an 091 with a 430HP motor is good! An 091 usually isn't good for more than 300HP for very long. I'm a firm believer the 2D would be a better match for 430HP, but in your case it would require lots of chassis work, longer axles (since the trans is skinnier), and one of the aftermarket nosecone kits (Funco or Transwerks) to help support the mainshaft. Your talking $8K-$9K by the time you get done. The other alternative is to keep the 091 and run less boost, say 4-5lbs to keep the HP down closer to 325 or so. You would likely be able to save some money on fuel also, running a blend instead of 110 octane. But seriously, 1 yr usage from that trans is good. Investing in a spare 091 trans may be a better way to go in your case.

So I spoke with Erick at Transworks today. We are going to put the 091 Plus in tomorrow. Billet nose cone and ball bearing input shaft bearing, new Weddle gears. Buggyworks is going to take care of the removal and install. New CV's while they are at it. Wanted to go with the Mendeola but just to much $$. Changing mouts, axles, $3000 more in tranny. Kill'n me. Anyone interested in a 37 year old classic female? No bondo only the finest silicone implants were ever installed on this model. Will trade for one bucket if CAT Desert Gold CV Grease, OBO. Let me know.

Oh, you guys gonna be out on the weekend after Halloween? Would like to shove a cold one or a Dirty Juanita (she is my specialty!) in your hand for the help. We will be at Gordons Friday night. Flag me down at the drags on Saturday.

Spoke with Eric at Transworks today...Looks like it was the Weddle Pinion that broke, not the ring gear. Bad gets worse the broken teeth got into the 2nd gears and beat them up too. So new ring and pinion, 1st, 2nd and their new billet nose cone. The guy over at Transworks are top notch and very much on the up and up, nice to find that is still around. Fast too. Car will be ready on Wednesday.

JDubYa