Q on differential adjustment

[dudespine]

Hi All, As part of my snapped axle project I went ahead and replaced the pinion housing bearings. Playing with combinations of the shims behind the housing's flange I can get .008 backlash as measured at the perimeter of the crown gear (the manual says .007-.010 between pinion and crown, but doesn't say where the measurement is taken). When comparing forward and reverse rotation, reverse is noticeably smoother and quieter. To get them equalized brings me out of spec for backlash (.014). So, is noisy in forward normal due to gear design, or do I adjust it out and live with the excess backlash? Or, does .014 at the crown gear perimeter equate somewhat to the backlash referenced in the manual? Thanks, Mike

[E.Worpe]

Hi Mike, The pinion housing adjustment enables the correct overlap of the pinion's teeth with the crown wheel's teeth to be set up. This is usually set with a jig, that correctly positions the pinion with respect to the crown wheel's bearing carriers. The crown wheel is then adjusted for the correct backlash by means of the two large nuts either side of the crown wheel carrier, which are also used to set up some preload on the bearings. To set things up correctly needs skill. If the previous backlash was about also 0.014 thou., then your crown wheel and pinion would have worn in a particular way. This may influence, in a detrimental way, how the teeth mesh when set up with the corect backlash. Regards, Eric. -----Original Message----- Hi All, As part of my snapped axle project I went ahead and replaced the pinion housing bearings. Playing with combinations of the shims behind the housing's flange I can get .008 backlash as measured at the perimeter of the crown gear (the manual says .007-.010 between pinion and crown, but doesn't say where the measurement is taken). When comparing forward and reverse rotation, reverse is noticeably smoother and quieter. To get them equalized brings me out of spec for backlash (.014). So, is noisy in forward normal due to gear design, or do I adjust it out and live with the excess backlash? Or, does .014 at the crown gear perimeter equate somewhat to the backlash referenced in the manual? Thanks, Mike [Non-text portions of this message have been removed]

[Donald Wilkinson]

digitaldon notes that none of the learned graybeards here, have suggested the use of prussian blue paste, or red lead paste (!!! Gawd!! did he say RED LEAD?!!!) in setting up this gearset, in order to observe actual gear tooth contact. Instructions for doing this are widely available in engineering texts and in the Brown Book. Sherrell considers this a black art, best left to "experts". Dunno, mebbe so. digitaldon has had reasonable success with this over the years. Don TC 7993

[Paroor]

This a single word remedy in Europe. ROGER Furneaux Madhu -----Urspr ngliche Nachricht----- Von: mg-tabc@yahoogroups.com [mailto:mg-tabc@yahoogroups.com]Im Auftrag von Donald Wilkinson Gesendet: Freitag, 20. Mai 2005 23:07 digitaldon notes that none of the learned graybeards here, have suggested the use of prussian blue paste, or red lead paste (!!! Gawd!! did he say RED LEAD?!!!) in setting up this gearset, in order to observe actual gear tooth contact. Instructions for doing this are widely available in engineering texts and in the Brown Book. Sherrell considers this a black art, best left to "experts". Dunno, mebbe so. digitaldon has had reasonable success with this over the years. Don TC 7993

[Jeff Redman]

'GAWD... Did he say RED LEAD?) Off on a tangent... Red Lead may now be considered a social bogey, but I confess to favour its use in the re-timbering of my toys. If it's good enough for old boat builders, then it's good enough for me. 'They'... the experts... claim it's harmful and leads to brain damage. 'They' are provably right... as witness my scribblings. Reddo with orange stuff under the fingernails -----Original Message----- From: mg-tabc@yahoogroups.com [mailto:mg-tabc@yahoogroups.com] On Behalf Of Donald Wilkinson Sent: Saturday, 21 May 2005 7:07 AM To: E.Worpe@surrey.ac.uk; mdudasik@optonline.net; mg-tabc@yahoogroups.com Subject: RE: [mg-tabc] Q on differential adjustment digitaldon notes that none of the learned graybeards here, have suggested the use of prussian blue paste, or red lead paste (!!! Gawd!! did he say RED LEAD?!!!) in setting up this gearset, in order to observe actual gear tooth contact. Instructions for doing this are widely available in engineering texts and in the Brown Book. Sherrell considers this a black art, best left to "experts". Dunno, mebbe so. digitaldon has had reasonable success with this over the years. Don TC 7993 Yahoo! Groups Links

[ROSS TAYLOR]

One of the best publications for setting up the TC crownwheel and pinion set is the Morris 8 workshop manual . I used it ( using prussian blue ) to set up diff in the TC in 1970 and again when the carrier broke in 1982. Could now be difficult to locate a copy, but with a bit of patience you CAN set up up your own diff. Other things are a black art to me, ie Voltage regulators, but with the right gear and NOT using the workshop manual as a last resort these can also be sorted out, Regards Ross In Tea Gardens

>digitaldon notes that none of the learned graybeards here, have suggested >the use of prussian blue paste, or red lead paste (!!! Gawd!! did he say >RED >LEAD?!!!) in setting up this gearset, in order to observe actual gear tooth >contact. Instructions for doing this are widely available in engineering >texts and in the Brown Book. Sherrell considers this a black art, best >left >to "experts". Dunno, mebbe so. digitaldon has had reasonable success with >this over the years. > >Don >TC 7993 > > > > > >Yahoo! Groups Links > > > > > >

[ROSS TAYLOR]

smee again Red lead and tallow used to be used as a gasket cement and anti seize compound in all the heavy fitting shops at the Newcastle BHP Steelworks for decades and plumbago and glycerene made a good "locktite " Blasts from the past Ross in Tea Gardens

>digitaldon notes that none of the learned graybeards here, have suggested >the use of prussian blue paste, or red lead paste (!!! Gawd!! did he say >RED >LEAD?!!!) in setting up this gearset, in order to observe actual gear tooth >contact. Instructions for doing this are widely available in engineering >texts and in the Brown Book. Sherrell considers this a black art, best >left >to "experts". Dunno, mebbe so. digitaldon has had reasonable success with >this over the years. > >Don >TC 7993 > > > > > >Yahoo! Groups Links > > > > > >

[Roger Furneaux]

hi Mike - if you only replaced the pinion bearings, then in theory you should replace the pinion housing with the same shims. When setting up diffs, the pinion position must be set first, as Eric has pointed out. With the new gears I supply, this "mounting distance" is engraved on each pinion, and an easily-made jig plus feeler gauges sets this m/d precisely. All old gears I have seen do not give this information, but as a starting point, put in .014" of shims , when the end face of the pinion should be almost level with the inside face of the diff gear teeth. Then adjust the backlash with the two large c/w bearing nuts; I use a dial gauge held in a little bracket bolted to a flange hole, with the plunger close to the outside edge of the teeth. Do this at several places because crownwheels very rarely run absolutely true, and b/l will vary around the periphery (must not be less than .005"/.12mm). Then get busy with the Prussian blue oil paint (buy a small tube from an art shop) or proper engineers blue (in a tube, not the spray-on marking blue which drys to a thin hard film). If after all this, the diff. is slightly noisy, it is possible to just remove the pinion housing and adjust shims by a thou or two. ocTagonally TCRoger, Devon, Olde England (where it is still rather wet...) Mike Dudasik wrote:

>As part of my snapped axle project I went ahead and replaced the pinion >housing bearings. Playing with combinations of the shims behind the >housing's flange I can get .008 backlash as measured at the perimeter >of the crown gear (the manual says .007-.010 between pinion and crown, >but doesn't say where the measurement is taken). When comparing forward >and reverse rotation, reverse is noticeably smoother and quieter. To >get them equalized brings me out of spec for backlash (.014). So, is >noisy in forward normal due to gear design, or do I adjust it out and >live with the excess backlash? Or, does .014 at the crown gear >perimeter equate somewhat to the backlash referenced in the manual?

[Non-text portions of this message have been removed]

[David Lodge]

Hello Rosscoe, I seem to remember my Great Aunt Alice suffered from plumbago ! Seriously though, that's a word I haven't seen or heard in tears! Best, D ----- ORIGINAL MESSAGE ----- From: "ROSS TAYLOR" rossmvt@msn.com> To: digitaldon@hotmail.com,E.Worpe@surrey.ac.uk,mdudasik@optonline.net,mg-tabc@yahoogroups.com Subject: RE: [mg-tabc] Q on differential adjustment Date: 22.5.2005 - 4:30:40

> smee again > Red lead and tallow used to be used as a gasket cement > and anti seize > compound in all the heavy fitting shops at the > Newcastle BHP Steelworks for > decades and plumbago and glycerene made a good > "locktite " Blasts from the > past > Ross in Tea Gardens > > >digitaldon notes that none of the learned graybeards > >here, have suggested > >the use of prussian blue paste, or red lead paste (!!! > >Gawd!! did he say > >RED > >LEAD?!!!) in setting up this gearset, in order to > >observe actual gear tooth > >contact. Instructions for doing this are widely > >available in engineering > >texts and in the Brown Book. Sherrell considers this > >a black art, best > >left > >to "experts". Dunno, mebbe so. digitaldon has had > >reasonable success with > >this over the years. > > > >Don > >TC 7993 > > > > > > > > > > > >Yahoo! Groups Links > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > >

[David Lodge]

Years, either, for that matter! ----- ORIGINAL MESSAGE ----- From: "David Lodge" archie_ponsonby@post.cz> To: rossmvt@msn.com,digitaldon@hotmail.com,E.Worpe@surrey.ac.uk,mdudasik@optonline.net,mg-tabc@yahoogroups.com Subject: Re: RE: [mg-tabc] Q on differential adjustment Date: 23.5.2005 - 20:38:38

> Hello Rosscoe, > > I seem to remember my Great Aunt Alice suffered from > plumbago > ! Seriously though, that's a word I haven't seen > or heard > in tears! > > Best, D > > > > ----- ORIGINAL MESSAGE ----- > From: "ROSS TAYLOR" rossmvt@msn.com> > To: >

digitaldon@hotmail.com,E.Worpe@surrey.ac.uk,mdudasik@optonline.net,mg-tabc@yahoogroups.com

> Subject: RE: [mg-tabc] Q on differential adjustment > Date: 22.5.2005 - 4:30:40 > > > smee again > > Red lead and tallow used to be used as a gasket > > cement > > and anti seize > > compound in all the heavy fitting shops at the > > Newcastle BHP Steelworks for > > decades and plumbago and glycerene made a good > > "locktite " Blasts from the > > past > > Ross in Tea Gardens > > > > >digitaldon notes that none of the learned graybeards > > >here, have suggested > > >the use of prussian blue paste, or red lead paste > > >(!!! > > >Gawd!! did he say > > >RED > > >LEAD?!!!) in setting up this gearset, in order to > > >observe actual gear tooth > > >contact. Instructions for doing this are widely > > >available in engineering > > >texts and in the Brown Book. Sherrell considers > > >this > > >a black art, best > > >left > > >to "experts". Dunno, mebbe so. digitaldon has had > > >reasonable success with > > >this over the years. > > > > > >Don > > >TC 7993 > > > > > > > > > > > > > > > > > >Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > >