New Goodie
- Thread starter KellyW
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Grippy little bugger
Dumb question, but... What clunk does this remove? I've got several. 
- Thread starter
- #6
It is used on 88-90 fj 62's with the auto.
This gear replaces the input gear-spacer-pto gear in the transfer case. The auto trucks wear at the output shaft of the transmission where it enters the transfer case. The problem is where the large input gear slides onto the output shaft causing a clunk when shifting from park or as my truck is developing a clunk upon upshift and downshift.
The problem is two fold 1. the splines on both the output shaft of the trans and on the inside portion of the input gear wear causing a gear wobble and slop as they both wear out and 2. as the splines wear the seals get beat up as well as allowing the atf to migrate from the auto into the transfer case and vise versa.
The Mcnamara gear is a one piece design that replaces the 3 original components, TC input gear, spacer and pto gear (not used in us models but installed at factory) with this one piece fully splined input gear that allows the use of an additional 56mm of the auto input shaft thus refreshing the entire setup and eliminating the slop from the worn spline section of shaft and inner splined section of the stock input gear.
This gear replaces the input gear-spacer-pto gear in the transfer case. The auto trucks wear at the output shaft of the transmission where it enters the transfer case. The problem is where the large input gear slides onto the output shaft causing a clunk when shifting from park or as my truck is developing a clunk upon upshift and downshift.
The problem is two fold 1. the splines on both the output shaft of the trans and on the inside portion of the input gear wear causing a gear wobble and slop as they both wear out and 2. as the splines wear the seals get beat up as well as allowing the atf to migrate from the auto into the transfer case and vise versa.
The Mcnamara gear is a one piece design that replaces the 3 original components, TC input gear, spacer and pto gear (not used in us models but installed at factory) with this one piece fully splined input gear that allows the use of an additional 56mm of the auto input shaft thus refreshing the entire setup and eliminating the slop from the worn spline section of shaft and inner splined section of the stock input gear.
Hope it takes care of your clunk. I made the assumption my clunk was caused by shaft wear and got the Mcnamara, but my assumption was false. 
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Kelly...nice write-up. Just a few more questions:
1. What is the address and email of the manufacturer or retailer of the Mcnamara Gear?
2. Will you be replacing the output shaft that will probably show spline damage?
3. Do you expect any gear "whine" with the meshng of new and old gears?
4. Any Write-up planned on the installation process?
1. What is the address and email of the manufacturer or retailer of the Mcnamara Gear?
2. Will you be replacing the output shaft that will probably show spline damage?
3. Do you expect any gear "whine" with the meshng of new and old gears?
4. Any Write-up planned on the installation process?
Here's the website: Jack McNamara - Differential Specialists
For #2, the point of using this gear is to avoid replacing the output shaft.
#3, I didn't expect it, nor did I get it.
#4. there may already be a write up on file. Check the FAQ for 60 series.
For #2, the point of using this gear is to avoid replacing the output shaft.
#3, I didn't expect it, nor did I get it.
#4. there may already be a write up on file. Check the FAQ for 60 series.
Kelly,
I'm still not sure. At one time I thought it was related to my gas tank having one broken retaining strap, but after getting a new tank for free in the recall and replacing the broken strap, it was still there. Up on the rack, there's a little slack at both ends of the drivetrain. My friend who did the Mac gear is a professional mechanic specializing in auto trannies. He thinks the clunk is not worth an intervention, at least not at this time. After a recent 3300 mile road trip, it's no worse.
I'm still not sure. At one time I thought it was related to my gas tank having one broken retaining strap, but after getting a new tank for free in the recall and replacing the broken strap, it was still there. Up on the rack, there's a little slack at both ends of the drivetrain. My friend who did the Mac gear is a professional mechanic specializing in auto trannies. He thinks the clunk is not worth an intervention, at least not at this time. After a recent 3300 mile road trip, it's no worse.