Hi guys,
Quick summary of what's been done so far - new Truetrac, new NV4500, recently rebuilt HD rear output case from WH, recently rebuilt/balanced driveshaft. The truck begins to roar starting at 30mph or so, and gets progressively worse as speed increases. This only happens under load/throttle. The noise has been described as "sounding like a 40's tractor" by a recent mechanic.
I've now moved on to the gears in the Dana 20. Upon brief inspection within the case, there was some scouring in some of the valleys on the RWD small gear.
I called and left a message for Jack O'Brien from O'Brien Four Wheel West, because the truck was sold to me as having his gears in the Dana. After beginning the teardown, I compared part numbers and found out the gears were actually TeraLows.
Jack called me back and was a wealth of knowledge. He mentioned that some of the early TeraLows were of poor quality because of the way they were cast/machined. Though I don't know when these gears were purchased (no receipt in the records I was given), it seems like most of the "recent" work on this truck was done in/around 2008 (per other receipts), and that general time corresponds to the first posts about these gears around the web.
Anyway - Jack of course recommended a set of his gears, but I'm not in the market for an expensive set. He also mentioned the original Spicer gears for the early cases (the 18-tooth versions) were the best quality of the originals. I recently got an older Dana 20 for parts, and it had the 18-tooth gears, so I pulled those out.
In beginning to swap the gears on the upper section of the Dana, I realized that there was a BIG difference in the fore/aft movement between the Teralow input gear and the original Spicer input gear - videos below. Is this normal, or could this be part of my problem?
Teralow gear - https://youtu.be/18CcOG5ygbc
Original Spicer - https://youtu.be/a2wrrUN1fLc
Additionally, there is some play (about 1/8") laterally when the gear is placed into the shift fork. This play is between the gear contact surface and the shift fork. In checking the play on my current transfer case vs the parts transfer case, there was less lateral play on the original case/fork. Is this normal, or could the fork begin to rattle against the gear at higher speed, causing it to roar?
Basically, I want this to be the last time I take the transfer case apart, so if the fork needs to be replaced, I'd rather do it now.
Thanks for the help!
Quick summary of what's been done so far - new Truetrac, new NV4500, recently rebuilt HD rear output case from WH, recently rebuilt/balanced driveshaft. The truck begins to roar starting at 30mph or so, and gets progressively worse as speed increases. This only happens under load/throttle. The noise has been described as "sounding like a 40's tractor" by a recent mechanic.
I've now moved on to the gears in the Dana 20. Upon brief inspection within the case, there was some scouring in some of the valleys on the RWD small gear.
I called and left a message for Jack O'Brien from O'Brien Four Wheel West, because the truck was sold to me as having his gears in the Dana. After beginning the teardown, I compared part numbers and found out the gears were actually TeraLows.
Jack called me back and was a wealth of knowledge. He mentioned that some of the early TeraLows were of poor quality because of the way they were cast/machined. Though I don't know when these gears were purchased (no receipt in the records I was given), it seems like most of the "recent" work on this truck was done in/around 2008 (per other receipts), and that general time corresponds to the first posts about these gears around the web.
Anyway - Jack of course recommended a set of his gears, but I'm not in the market for an expensive set. He also mentioned the original Spicer gears for the early cases (the 18-tooth versions) were the best quality of the originals. I recently got an older Dana 20 for parts, and it had the 18-tooth gears, so I pulled those out.
In beginning to swap the gears on the upper section of the Dana, I realized that there was a BIG difference in the fore/aft movement between the Teralow input gear and the original Spicer input gear - videos below. Is this normal, or could this be part of my problem?
Teralow gear - https://youtu.be/18CcOG5ygbc
Original Spicer - https://youtu.be/a2wrrUN1fLc
Additionally, there is some play (about 1/8") laterally when the gear is placed into the shift fork. This play is between the gear contact surface and the shift fork. In checking the play on my current transfer case vs the parts transfer case, there was less lateral play on the original case/fork. Is this normal, or could the fork begin to rattle against the gear at higher speed, causing it to roar?
Basically, I want this to be the last time I take the transfer case apart, so if the fork needs to be replaced, I'd rather do it now.
Thanks for the help!
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