Topic: grinding noises looking for ideas

[85yotanh]

I recently put my truck back together from a motor rebuild. When putting it back together i put in a crawl box, and twin sticks in the rear case which has 4.7 gears.

its an 85
standard
marlin crawl box 2.28
top shift rear case 4.7
twin sticks

The engine runs great, I finally put it back down on all four wheels the other night and took it out for a spin.

on take off you don't really notice any sounds but literally as soon as i shift into 3rd gear I start hearing a clicking/grinding noise (almost like two gears are lightly rubbing each other ever so slightly). it contiues up through the other gears but jost gets so fast its a constant sound. when I depress the clutch and roll up to a stop sign the clicking slows gradually and slowly comes to a stop. that last part is the part that really doesnt make sense to me because the sound while driving usually only happens under load or when im on the gas. you can literally here it slow to its last tick. At the moment I still have a huge hole in my floor so everything is very loud. the noise sounds like its coming from ahead of me like directly beneath the dashboard floor.

With that said though, everything seems to be shifting fine. the clutch engages well it rolls smoothly down the road 4wd and 2wd engage and 4 low and 4 lower. I had it up to 45-50 mph and everything was great except this awful noise. In all honesty I tried search this out but its awfully strange issue.

I am headed back to dig in to the problem tonight, but I honestly couldn't even grasp what it could be.

any suggestions or thoughts would be much appreciated.

Thanks in advance

[emsvitil]

What transmission? (L series,W series, R series) ?

How many miles on transmission?

[TheChewMaster]

prob a w or g series tranny. are you sure its not your rear drive line, this can be a common problem for guys driving at speed, but usually the noise comes when you drop off the gas.

I had a similar problem, my rear output flange was loose. the steak nut was really old and would not stay in place. got new ones from toyota, works great. and this noise occured during accelaration

[85yotanh [OP]]

Its a w I believe, and theres 124,000

the output flange seems right but it may have gotten knocked around somewhere along the way. I do know that I installed the 4.7 gears 2 years ago and everything including the flanges were gone through and torqued meticulously. Not to say that these things don't come loose

[Steve_925]

if you have a CV on your driveline it may be that. try pulling the shaft and drive it in 4wd to see if the noise is still there

[Nimyad]

My bet's on needing a rear cv joint.

[85yotanh [OP]]

After looking at it tonight I drove it in front wheel drive and the noise was much quieter but I think it may be the clutch the cv in the rear is a custom 3/4ton cv shaft made by a local shop it might have 4000 miles on it. If the clutch Disk was put in backwards what it clatter? I guess what would the symptoms be if the clutch was installed wrong? Would it still drive? This ... Whatever it is sounds awful.

Any thoughts are appreciated!

[toyodaaddict]

did you adjust the pinion angle after installing the crawl box?

[85yotanh [OP]]

did you adjust the pinion angle after installing the crawl box?

as in did i rotate the axle? if so the answer is no it is still in the stock location.

Also the noise is like a screaching chatter at higher speeds I absolutely had to drive it home from my friends house last night and in fifth gear when I let off the gas like a screeching grinding noise would occur for about 3 seconds and then it would be just a grinding until i got on the gas again which it would screech / grind for another couple seconds and just grinding again. the sound definately sounds like it coming in straight from the bellhousing, but I could be wrong. Is it possibly to have the clutch adjusted wrong so there is interference, or I guess what could be the the potential problems.

things i know:

driveline is tight
out put flange is torqued to spec and is nice and snug
the is no physical interferance with either drive shafts
the noise sounds like it is coming from a space behind the engine and ahead of the t-cases
it clunks kinda heavy letting the clutch in and out
the more load the heavier the noise
letting off the gas results in like a screeching grinding from said area.

I know it is pretty easy to flip the clutch disk if you arent paying attention, but I am not sure of what the symptoms are for this.

any thoughts are helpful

[HogCanyonHopper]

you need to get some pictures up so we can see your pinion angle. It should point right at your t-case and have just a few degrees angle. I had a really bad noise from my tranny before I installed a cv driveline. If your pinion angle is good, and you are already running a cv, then your looking at bad bearings or something like that in the tranny. Pics of your dl setup would be helpful. Pulling your tranny and inspecting the clutch may be inevitable.

[toyodaaddict]

i dont know what happens when you put a clutch in backwards but i can tell you for sure that with a cv your rear pinion flange needs to be pointed at the tcase output. i find setting them 2* under the slope of the shaft works best. i use steel shims from 4crawler.com

[amm9130]

As far as I kno the clutch shouldn't have any effect. My dad bought a geo metro and had it for about 5 years and then the clutch started giving trouble. He took it to the mechanic and helped him put in a new clutch. turns out the old clutch was in backwards ever sence he had it